diff --git a/tests/test_data.py b/tests/test_data.py
index 44bea81..3ea9165 100644
--- a/tests/test_data.py
+++ b/tests/test_data.py
@@ -3,9 +3,12 @@
 # which is available at https://opensource.org/licenses/MIT
 
 import pandas as pd
+from numpy.testing import assert_almost_equal
 
 from mltb2.data import _load_colon_data, _load_colon_label, load_colon, load_leukemia_big, load_prostate
 
+from .ori_data_loader import load_colon_data, load_leukemia_data, load_prostate_data
+
 
 def test_load_colon_data():
     result = _load_colon_data()  # only load data not labels
@@ -32,6 +35,15 @@ def test_load_colon():
     assert result[1].shape == (62, 2000)
 
 
+def test_load_colon_compare_original():
+    result = load_colon()
+    ori_result = load_colon_data()
+    assert result[0].shape == ori_result[0].shape
+    assert result[1].shape == ori_result[1].shape
+    assert_almost_equal(result[0].to_numpy(), ori_result[0].to_numpy())
+    assert_almost_equal(result[1].to_numpy(), ori_result[1].to_numpy())
+
+
 def test_load_prostate():
     result = load_prostate()
     assert result is not None
@@ -43,6 +55,15 @@ def test_load_prostate():
     assert result[1].shape == (102, 6033)
 
 
+def test_load_prostate_compare_original():
+    result = load_prostate()
+    ori_result = load_prostate_data()
+    assert result[0].shape == ori_result[0].shape
+    assert result[1].shape == ori_result[1].shape
+    assert_almost_equal(result[0].to_numpy(), ori_result[0].to_numpy())
+    assert_almost_equal(result[1].to_numpy(), ori_result[1].to_numpy())
+
+
 def test_load_leukemia_big():
     result = load_leukemia_big()
     assert result is not None
@@ -52,3 +73,12 @@ def test_load_leukemia_big():
     assert isinstance(result[1], pd.DataFrame)
     assert result[0].shape == (72,)
     assert result[1].shape == (72, 7128)
+
+
+def test_load_leukemia_big_compare_original():
+    result = load_leukemia_big()
+    ori_result = load_leukemia_data()
+    assert result[0].shape == ori_result[0].shape
+    assert result[1].shape == ori_result[1].shape
+    assert_almost_equal(result[0].to_numpy(), ori_result[0].to_numpy())
+    assert_almost_equal(result[1].to_numpy(), ori_result[1].to_numpy())