diff --git a/include/cdsl_defs.h b/include/cdsl_defs.h
index e85fbe9..5bd6a88 100644
--- a/include/cdsl_defs.h
+++ b/include/cdsl_defs.h
@@ -97,6 +97,9 @@ extern "C" {
 #define DECLARE_PRINTER(fn)    void fn(void* node)
 #endif
 
+/**!
+ *
+ */
 typedef void* (*cdsl_generic_compare_t)(void*, void*);
 typedef void (*cdsl_generic_printer_t) (void*);
 typedef void* (*cdsl_alloc_t)(unsigned long sz);
diff --git a/include/cdsl_dlist.h b/include/cdsl_dlist.h
index e5dc766..4131bc6 100644
--- a/include/cdsl_dlist.h
+++ b/include/cdsl_dlist.h
@@ -12,22 +12,25 @@
 #define CDSL_DLIST_H_
 
 #include "base_list.h"
+#include "sort.h"
 
 #if defined(__cplusplus)
 extern "C" {
 #endif
 
 
-#define cdsl_dlistIsEmpty(lhead) 			(((dlistEntry_t*) lhead)->head== NULL)
+#define cdsl_dlistIsEmpty(lhead)                      (((dlistEntry_t*) lhead)->head== NULL)
 
-#define cdsl_dlistSize(lentry)				cdsl_listSize((listEntry_t*) lentry)
-#define cdsl_dlistContain(lentry, item)		cdsl_listContain((listEntry_t*) lentry, (listNode_t*) item)
-#define cdsl_dlistPrint(lentry,print) 		cdsl_listPrint((listEntry_t*) lentry, print)
+#define cdsl_dlistSize(lentry)                        cdsl_listSize((listEntry_t*) lentry)
+#define cdsl_dlistContain(lentry, item)               cdsl_listContain((listEntry_t*) lentry, (listNode_t*) item)
+#define cdsl_dlistPrint(lentry,print)                 cdsl_listPrint((listEntry_t*) lentry, print)
 
 
-#define cdsl_dlistIterInit(lentry, iter)	cdsl_iterInit((listEntry_t*) lentry, iter)
-#define cdsl_dlistIterHasNext(iter)			cdsl_iterHasNext(iter)
-#define cdsl_dlistIterNext(iter)			cdsl_iterNext(iter)
+#define cdsl_dlistIterInit(lentry, iter)              cdsl_iterInit((listEntry_t*) lentry, iter)
+#define cdsl_dlistIterHasNext(iter)                   cdsl_iterHasNext(iter)
+#define cdsl_dlistIterNext(iter)                      cdsl_iterNext(iter)
+
+#define cdsl_dlistSort(lentry, order, compare)        cdsl_listMergeSort((listEntry_t*) lentry, order, compare, TRUE)
 
 typedef struct cdsl_dlnode dlistNode_t;
 typedef struct cdsl_dlentry dlistEntry_t;
diff --git a/include/cdsl_slist.h b/include/cdsl_slist.h
index 075a537..1c6277c 100644
--- a/include/cdsl_slist.h
+++ b/include/cdsl_slist.h
@@ -9,21 +9,24 @@
 #define CDSL_SLIST_H_
 
 #include "base_list.h"
+#include "sort.h"
 
 #if defined(__cplusplus)
 extern "C" {
 #endif
 
 
-#define cdsl_slistIsEmpty(node)				(((slistEntry_t*) node)->head == NULL)
+#define cdsl_slistIsEmpty(node)                          (((slistEntry_t*) node)->head == NULL)
 
-#define cdsl_slistSize(lentry)				cdsl_listSize((listEntry_t*) lentry)
-#define cdsl_slistContain(lentry, item)		cdsl_listContain((listEntry_t*) lentry, (listNode_t*) item)
-#define cdsl_slistPrint(lentry,print) 		cdsl_listPrint((listEntry_t*) lentry, print)
+#define cdsl_slistSize(lentry)                           cdsl_listSize((listEntry_t*) lentry)
+#define cdsl_slistContain(lentry, item)                  cdsl_listContain((listEntry_t*) lentry, (listNode_t*) item)
+#define cdsl_slistPrint(lentry,print)                    cdsl_listPrint((listEntry_t*) lentry, print)
+
+#define cdsl_slistIterInit(lentry, iter)                 cdsl_iterInit((listEntry_t*) lentry, iter)
+#define cdsl_slistIterHasNext(iter)                      cdsl_iterHasNext(iter)
+#define cdsl_slistIterNext(iter)                         cdsl_iterNext(iter)
+#define cdsl_slistSort(lentry, order, compare)           cdsl_listMergeSort((listEntry_t*) lentry, order, compare, FALSE)
 
-#define cdsl_slistIterInit(lentry, iter)	cdsl_iterInit((listEntry_t*) lentry, iter)
-#define cdsl_slistIterHasNext(iter)			cdsl_iterHasNext(iter)
-#define cdsl_slistIterNext(iter)			cdsl_iterNext(iter)
 
 typedef struct cdsl_slnode slistNode_t;
 typedef struct cdsl_slentry slistEntry_t;
diff --git a/include/sort.h b/include/sort.h
new file mode 100644
index 0000000..f7ef6ad
--- /dev/null
+++ b/include/sort.h
@@ -0,0 +1,29 @@
+
+
+#ifndef __CDSL_SORT_C
+#define __CDSL_SORT_C
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "base_list.h"
+
+typedef enum {
+	ASC,
+	DESC
+}sortOrder_t;
+/**
+ * @return positive if one is larger than the_other, or negative otherwise. 0 when the two are exactly same
+ */
+typedef int (*cdsl_comparator_t)(void* one, void* the_other);
+
+extern void cdsl_listMergeSort(listEntry_t* entry, sortOrder_t order, cdsl_comparator_t comp, BOOL isDoubleLink);
+
+#ifdef __cplusplus
+}
+#endif
+
+
+
+#endif
diff --git a/source/base_list.c b/source/base_list.c
index b7cacf6..92fe97a 100644
--- a/source/base_list.c
+++ b/source/base_list.c
@@ -76,7 +76,8 @@ listNode_t* cdsl_iterNext(listIter_t* iter)
 		return NULL;
 	if(!iter->prev)
 		iter->prev = (listNode_t*) iter->entry;
-	return iter->prev->next;
+	iter->prev = iter->prev->next;
+	return iter->prev;
 }
 
 listNode_t* cdsl_iterRemove(listIter_t* iter)
diff --git a/source/recipe.mk b/source/recipe.mk
index 84e4d61..f712c11 100644
--- a/source/recipe.mk
+++ b/source/recipe.mk
@@ -11,6 +11,7 @@ OBJ-y+= base_list\
 		cdsl_spltree\
 		cdsl_rbtree\
 		cdsl_hashtree\
-		baremetal
+		baremetal\
+		sort
 
 		
\ No newline at end of file
diff --git a/source/sort.c b/source/sort.c
new file mode 100644
index 0000000..1e6764f
--- /dev/null
+++ b/source/sort.c
@@ -0,0 +1,85 @@
+
+
+
+#include "cdsl_dlist.h"
+#include "sort.h"
+
+
+static listNode_t* merge_sort_rc(listNode_t* head, sortOrder_t order, cdsl_comparator_t comp, BOOL isDouble);
+static listNode_t* peek_middle(listNode_t* head);
+
+extern void cdsl_listMergeSort(listEntry_t* entry, sortOrder_t order, cdsl_comparator_t comp, BOOL isDoubleLink) {
+	entry->head = merge_sort_rc(entry->head, order, comp, isDoubleLink);
+}
+
+static listNode_t* merge_sort_rc(listNode_t* head, sortOrder_t order, cdsl_comparator_t comp, BOOL isDouble) {
+	if(!(head->next)) {
+		return head;
+	}
+	listNode_t* middle = peek_middle(head);
+	if(!middle) {
+		return head;
+	}
+	listNode_t* left_cur, *right_cur;
+	if(head->next == middle) {
+		head->next = NULL;
+		left_cur = head;
+		right_cur = merge_sort_rc(middle, order, comp, isDouble);
+	} else {
+		right_cur = merge_sort_rc(middle->next, order, comp, isDouble);
+		middle->next = NULL;
+		left_cur = merge_sort_rc(head, order, comp, isDouble);
+	}
+	head = NULL;
+	listNode_t** slot = &head;
+	// keep
+	// NOTE :  middle used as previous from this point
+	middle = NULL;
+	while(!((left_cur == NULL) && (right_cur == NULL))) {
+
+		if ((left_cur != NULL) && (right_cur != NULL)) {
+			if (comp(left_cur, right_cur) > 0) {
+				*slot = (order == ASC)? right_cur : left_cur;
+			} else {
+				*slot = (order == ASC)? left_cur : right_cur;
+			}
+		} else if (left_cur == NULL) {
+			*slot = right_cur;
+		} else {
+			*slot = left_cur;
+		}
+		if(*slot == left_cur) {
+			left_cur = left_cur->next;
+		} else if(*slot == right_cur) {
+			right_cur = right_cur->next;
+		}
+		if(isDouble) {
+			if(middle) {
+				((dlistNode_t*) *slot)->prev = (dlistNode_t*) middle;
+				middle = *slot;
+			} else {
+				middle = *slot;
+				((dlistNode_t*) middle)->prev = NULL;
+			}
+		}
+		slot = &(*slot)->next;
+	}
+	return head;
+}
+
+/***
+ *  head node of list chunk to be searched
+ *  @return head if there is only list node in the list chunk, otherwise return middle list node within the list chunk.
+ */
+static listNode_t* peek_middle(listNode_t* head) {
+	listNode_t* mid = head;
+	uint32_t l_cnt = 0;
+	while(head->next) {
+		if((l_cnt % 2) == 0) {
+			mid = mid->next;
+		}
+		l_cnt++;
+		head = head->next;
+	}
+	return mid;
+}
diff --git a/source/test/cdsl_list_test.c b/source/test/cdsl_list_test.c
index 643ec9e..86c0432 100644
--- a/source/test/cdsl_list_test.c
+++ b/source/test/cdsl_list_test.c
@@ -9,13 +9,14 @@
 #include <stdio.h>
 #include "cdsl_dlist.h"
 #include "cdsl_list_test.h"
-
+#include "sort.h"
 struct card {
 	dlistNode_t list_node;
 	int num;
 };
 
 static DECLARE_COMPARE_FN(compare);
+static int compare_sort(void* one, void* the_other);
 static struct card cards[TEST_SIZE];
 
 BOOL cdsl_listDoTest(void)
@@ -45,9 +46,33 @@ BOOL cdsl_listDoTest(void)
 		}
 	}
 
+	// test sort
+	for(idx = 0; idx < TEST_SIZE; idx++) {
+		cdsl_dlistNodeInit(&cards[idx].list_node);
+		cards[idx].num = idx;
+		cdsl_dlistPutHead(&list_entry, &(cards[idx].list_node));
+	}
+	cdsl_dlistSort(&list_entry, DESC, compare_sort);
+	listIter_t iter;
+	cdsl_iterInit((listEntry_t*) &list_entry, &iter);
+	int prev_num = TEST_SIZE;
+	while(cdsl_iterHasNext(&iter)) {
+		void* node = (void*) cdsl_iterNext(&iter);
+		struct card* cp = container_of(node, struct card, list_node);
+		if(prev_num < cp->num) {
+			return FALSE;
+		}
+		prev_num = cp->num;
+	}
 	return TRUE;
 }
 
+static int compare_sort(void* one, void* the_other) {
+	struct card* this_card = container_of(one, struct card, list_node);
+	struct card* that_card = container_of(the_other, struct card, list_node);
+	return this_card->num - that_card->num;
+}
+
 
 static DECLARE_COMPARE_FN(compare)
 {
diff --git a/source/test/cdsl_slist_test.c b/source/test/cdsl_slist_test.c
index eb60768..2af4e2e 100644
--- a/source/test/cdsl_slist_test.c
+++ b/source/test/cdsl_slist_test.c
@@ -21,6 +21,7 @@ typedef struct card {
 static card_t Cards[TEST_SIZE];
 static DECLARE_COMPARE_FN(card_compare);
 static slistEntry_t listEntry;
+static int compare_sort(void* one, void* the_other);
 
 
 BOOL cdsl_slistDoTest(void){
@@ -57,10 +58,34 @@ BOOL cdsl_slistDoTest(void){
 		if(!card)
 			return FALSE;
 	}
+	for(i = 0; i < TEST_SIZE; i++) {
+			cdsl_slistNodeInit(&Cards[i].list_head);
+			Cards[i].card_num = i;
+			cdsl_slistPutHead(&listEntry, &Cards[i].list_head);
+		}
+		cdsl_slistSort(&listEntry, DESC, compare_sort);
+		listIter_t iter;
+		cdsl_iterInit((listEntry_t*) &listEntry, &iter);
+		int prev_num = TEST_SIZE;
+		while(cdsl_iterHasNext(&iter)) {
+			void* node = (void*) cdsl_iterNext(&iter);
+			struct card* cp = container_of(node, struct card, list_head);
+			if(prev_num < cp->card_num) {
+				return FALSE;
+			}
+			prev_num = cp->card_num;
+		}
 	return TRUE;
 }
 
 
+static int compare_sort(void* one, void* the_other) {
+	struct card* this_card = container_of(one, struct card, list_head);
+	struct card* that_card = container_of(the_other, struct card, list_head);
+	return this_card->card_num - that_card->card_num;
+}
+
+
 static DECLARE_COMPARE_FN(card_compare){
 	if(!a)
 		return b;