diff --git a/x/registry/keeper/msg_server_register_top_level_domain_test.go b/x/registry/keeper/msg_server_register_top_level_domain_test.go
index e1db88f7..8b41a322 100644
--- a/x/registry/keeper/msg_server_register_top_level_domain_test.go
+++ b/x/registry/keeper/msg_server_register_top_level_domain_test.go
@@ -16,34 +16,33 @@ func (suite *KeeperTestSuite) TestRegisterTopLevelDomain() {
 		creator                  string
 		name                     string
 		registrationPeriodInYear uint64
-		domainOwnership          types.DomainOwnership
 		expErr                   error
 		fn                       func()
 	}{
 		{
 			creator:                  testutil.Alice,
-			name:                     "cel",
+			name:                     "cel0",
 			registrationPeriodInYear: 1,
 			expErr:                   nil,
 			fn:                       func() {},
 		},
 		{
 			creator:                  testutil.Alice,
-			name:                     "cel",
+			name:                     "cel1",
 			registrationPeriodInYear: 4,
 			expErr:                   nil,
 			fn:                       func() {},
 		},
 		{
 			creator:                  testutil.Alice,
-			name:                     "cel",
+			name:                     "cel2",
 			registrationPeriodInYear: 1,
-			expErr:                   sdkerrors.Wrapf(errors.New(fmt.Sprintf("foo.cel")), types.ErrDomainIsAlreadyTaken.Error()),
+			expErr:                   sdkerrors.Wrapf(errors.New(fmt.Sprintf("cel2")), types.ErrDomainIsAlreadyTaken.Error()),
 			fn: func() {
 				// Register domain once
 				domain := &types.MsgRegisterTopLevelDomain{
 					Creator:                  testutil.Alice,
-					Name:                     "cel",
+					Name:                     "cel2",
 					RegistrationPeriodInYear: 1,
 				}
 				_, err := suite.msgServer.RegisterTopLevelDomain(suite.ctx, domain)
@@ -69,7 +68,7 @@ func (suite *KeeperTestSuite) TestRegisterTopLevelDomain() {
 			_, err := suite.msgServer.RegisterTopLevelDomain(suite.ctx, registerMsg)
 			fmt.Println("----Case_", i, "---01", err)
 
-			if err == nil {
+			if tc.expErr == nil {
 				// Evalute if domain is registered
 				_, found := suite.app.RegistryKeeper.GetTopLevelDomain(suite.ctx, tc.name)
 				suite.Require().True(found)
@@ -79,10 +78,10 @@ func (suite *KeeperTestSuite) TestRegisterTopLevelDomain() {
 				events := sdk.StringifyEvents(suite.ctx.EventManager().ABCIEvents())
 				eventIndex := len(events) - 1
 				suite.Require().EqualValues(sdk.StringEvent{
-					Type: types.EventTypeRegsterDomain,
+					Type: types.EventTypeRegsterTopLevelDomain,
 					Attributes: []sdk.Attribute{
 						{Key: types.AttributeRegisterTopLevelDomainEventName, Value: tc.name},
-						{Key: types.AttributeRegisterTopLevelDomainEventExpirationDate, Value: events[eventIndex].Attributes[2].Value},
+						{Key: types.AttributeRegisterTopLevelDomainEventExpirationDate, Value: events[eventIndex].Attributes[1].Value},
 					},
 				}, events[eventIndex])
 			} else {
diff --git a/x/registry/keeper/register_top_level_domain.go b/x/registry/keeper/register_top_level_domain.go
new file mode 100644
index 00000000..ef8556a9
--- /dev/null
+++ b/x/registry/keeper/register_top_level_domain.go
@@ -0,0 +1,44 @@
+package keeper
+
+import (
+	// "errors"
+	// "fmt"
+	"github.com/mycel-domain/mycel/x/registry/types"
+	"strconv"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	// sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+)
+
+// Pay TLD registration fee
+func (k Keeper) PayTLDRegstrationFee(ctx sdk.Context, payer sdk.AccAddress, domain types.TopLevelDomain, registrationPeriodInYear uint64) (err error) {
+	// TODO: Pay fee
+	return nil
+}
+
+func (k Keeper) RegisterTopLevelDomain(ctx sdk.Context, domain types.TopLevelDomain, owner sdk.AccAddress, registrationPeriodIYear uint64) (err error) {
+	// Validate domain
+	err = k.ValidateTopLevelDomain(ctx, domain)
+	if err != nil {
+		return err
+	}
+
+	// Pay TLD registration fee
+	err = k.PayTLDRegstrationFee(ctx, owner, domain, registrationPeriodIYear)
+	if err != nil {
+		return err
+	}
+
+	// Set domain
+	k.SetTopLevelDomain(ctx, domain)
+
+	// Emit event
+	ctx.EventManager().EmitEvent(
+		sdk.NewEvent(types.EventTypeRegsterTopLevelDomain,
+			sdk.NewAttribute(types.AttributeRegisterTopLevelDomainEventName, domain.Name),
+			sdk.NewAttribute(types.AttributeRegisterTopLevelDomainEventExpirationDate, strconv.FormatInt(domain.ExpirationDate, 10)),
+		),
+	)
+
+	return err
+}
diff --git a/x/registry/keeper/validate_registration.go b/x/registry/keeper/validate_registration.go
index 36c59f8a..7e54197f 100644
--- a/x/registry/keeper/validate_registration.go
+++ b/x/registry/keeper/validate_registration.go
@@ -22,12 +22,15 @@ func (k Keeper) GetIsParentDomainExist(ctx sdk.Context, domain types.SecondLevel
 	return isParentDomainExist
 }
 
+// Get is domain already taken
+func (k Keeper) GetIsTopLevelDomainAlreadyTaken(ctx sdk.Context, domain types.TopLevelDomain) (isDomainAlreadyTaken bool) {
+	_, isDomainAlreadyTaken = k.GetTopLevelDomain(ctx, domain.Name)
+	return isDomainAlreadyTaken
+}
+
 // Validate TLD registration
-func (k Keeper) ValidateRegisterTLD(ctx sdk.Context, domain types.SecondLevelDomain) (err error) {
-	if domain.Parent != "" {
-		err = sdkerrors.Wrapf(errors.New(domain.Parent),
-			types.ErrParentDomainMustBeEmpty.Error())
-	}
+func (k Keeper) ValidateRegisterTLD(ctx sdk.Context, domain types.TopLevelDomain) (err error) {
+	// TODO: Validate TLD
 	// TODO: Is Staked enough to register TLD
 	return err
 }
@@ -84,3 +87,27 @@ func (k Keeper) ValidateSecondLevelDomain(ctx sdk.Context, domain types.SecondLe
 
 	return err
 }
+
+// Validate top-level-domain
+func (k Keeper) ValidateTopLevelDomain(ctx sdk.Context, domain types.TopLevelDomain) (err error) {
+	// Type check
+	err = domain.Validate()
+	if err != nil {
+		return err
+	}
+	// Check if domain is already taken
+	isDomainAlreadyTaken := k.GetIsTopLevelDomainAlreadyTaken(ctx, domain)
+	if isDomainAlreadyTaken {
+		err = sdkerrors.Wrapf(errors.New(fmt.Sprintf("%s", domain.Name)),
+			types.ErrDomainIsAlreadyTaken.Error())
+		return err
+	}
+
+	// Validate TLD
+	err = k.ValidateRegisterTLD(ctx, domain)
+	if err != nil {
+		return err
+	}
+
+	return err
+}