diff --git a/pkg/scheduler/core/generic_scheduler_test.go b/pkg/scheduler/core/generic_scheduler_test.go
index cdc2dee2c218..f78fd4b53b3c 100644
--- a/pkg/scheduler/core/generic_scheduler_test.go
+++ b/pkg/scheduler/core/generic_scheduler_test.go
@@ -17,6 +17,8 @@ limitations under the License.
 package core
 
 import (
+	"strconv"
+	"strings"
 	"testing"
 
 	clusterv1alpha1 "github.com/karmada-io/karmada/pkg/apis/cluster/v1alpha1"
@@ -25,19 +27,44 @@ import (
 	"github.com/karmada-io/karmada/test/helper"
 )
 
-// Test Case of even distribution of replicas, case 1
-// 1. create deployment (replicas=3), weight=1:1
-// 2. check two member cluster replicas, should be 2:1 or 1:2
-func Test_genericScheduler_AssignReplicas(t *testing.T) {
-	tests := []struct {
-		name      string
-		clusters  []*clusterv1alpha1.Cluster
-		placement *policyv1alpha1.Placement
-		object    *workv1alpha2.ResourceBindingSpec
-		wants     [][]workv1alpha2.TargetCluster
-		wantErr   bool
-	}{
+type testcase struct {
+	name      string
+	clusters  []*clusterv1alpha1.Cluster
+	object    *workv1alpha2.ResourceBindingSpec
+	placement *policyv1alpha1.Placement
+	// changeCondForNextSchedule following cases will schedule twice, this function aims to change the schedule condition for second schedule
+	changeCondForNextSchedule func(tt *testcase)
+	// wants key is first time schedule possible result, value is second time schedule possible result
+	wants   map[string][]string
+	wantErr bool
+}
+
+var clusterToIndex = map[string]int{
+	ClusterMember1: 0,
+	ClusterMember2: 1,
+	ClusterMember3: 2,
+	ClusterMember4: 3,
+}
+
+// isScheduleResultEqual change []workv1alpha2.TargetCluster to the string format just like 1:1:1, and compare it to expect string
+func isScheduleResultEqual(tcs []workv1alpha2.TargetCluster, expect string) bool {
+	res := make([]string, len(tcs))
+	for _, cluster := range tcs {
+		idx := clusterToIndex[cluster.Name]
+		res[idx] = strconv.Itoa(int(cluster.Replicas))
+	}
+	actual := strings.Join(res, ":")
+	return actual == expect
+}
+
+// These are acceptance test cases given by QA for requirement: dividing replicas by static weight evenly
+// https://github.com/karmada-io/karmada/issues/4220
+func Test_EvenDistributionOfReplicas(t *testing.T) {
+	tests := []*testcase{
 		{
+			// Test Case No.1 of even distribution of replicas
+			// 1. create deployment (replicas=3), weight=1:1
+			// 2. check two member cluster replicas, should be 2:1 or 1:2
 			name: "replica 3, static weighted 1:1",
 			clusters: []*clusterv1alpha1.Cluster{
 				helper.NewCluster(ClusterMember1),
@@ -58,32 +85,85 @@ func Test_genericScheduler_AssignReplicas(t *testing.T) {
 					},
 				},
 			},
-			wants: [][]workv1alpha2.TargetCluster{
-				{
-					{Name: ClusterMember1, Replicas: 1},
-					{Name: ClusterMember2, Replicas: 2},
-				},
-				{
-					{Name: ClusterMember1, Replicas: 2},
-					{Name: ClusterMember2, Replicas: 1},
+			changeCondForNextSchedule: nil,
+			wants: map[string][]string{
+				"1:2": {},
+				"2:1": {},
+			},
+			wantErr: false,
+		},
+		{
+			// Test Case No.2 of even distribution of replicas
+			// 1. create deployment (replicas=3), weight=1:1:1
+			// 2. check three member cluster replicas, should be 1:1:1
+			// 3. update replicas from 3 to 5
+			// 4. check three member cluster replicas, should be 2:2:1 or 2:1:2 or 1:2:2
+			name: "replica 3, static weighted 1:1:1, change replicas from 3 to 5",
+			clusters: []*clusterv1alpha1.Cluster{
+				helper.NewCluster(ClusterMember1),
+				helper.NewCluster(ClusterMember2),
+				helper.NewCluster(ClusterMember3),
+			},
+			object: &workv1alpha2.ResourceBindingSpec{
+				Replicas: 3,
+			},
+			placement: &policyv1alpha1.Placement{
+				ReplicaScheduling: &policyv1alpha1.ReplicaSchedulingStrategy{
+					ReplicaSchedulingType:     policyv1alpha1.ReplicaSchedulingTypeDivided,
+					ReplicaDivisionPreference: policyv1alpha1.ReplicaDivisionPreferenceWeighted,
+					WeightPreference: &policyv1alpha1.ClusterPreferences{
+						StaticWeightList: []policyv1alpha1.StaticClusterWeight{
+							{TargetCluster: policyv1alpha1.ClusterAffinity{ClusterNames: []string{ClusterMember1}}, Weight: 1},
+							{TargetCluster: policyv1alpha1.ClusterAffinity{ClusterNames: []string{ClusterMember2}}, Weight: 1},
+							{TargetCluster: policyv1alpha1.ClusterAffinity{ClusterNames: []string{ClusterMember3}}, Weight: 1},
+						},
+					},
 				},
 			},
+			changeCondForNextSchedule: func(tt *testcase) {
+				tt.object.Replicas = 5
+			},
+			wants: map[string][]string{
+				"1:1:1": {"2:2:1", "2:1:2", "1:2:2"},
+			},
 			wantErr: false,
 		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			g := &genericScheduler{}
+			var g = &genericScheduler{}
+			var firstScheduleResult, secondScheduleResult string
+
+			// 1. schedule for the first time, and check whether first schedule result within tt.wants
 			got, err := g.assignReplicas(tt.clusters, tt.placement, tt.object)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("AssignReplicas() error = %v, wantErr %v", err, tt.wantErr)
 				return
 			}
-			if tt.wantErr {
+			for firstScheduleResult = range tt.wants {
+				if isScheduleResultEqual(got, firstScheduleResult) {
+					break
+				}
+			}
+			if !isScheduleResultEqual(got, firstScheduleResult) {
+				t.Errorf("AssignReplicas() got = %v, wants %v", got, tt.wants)
+				return
+			}
+
+			// 2. change the schedule condition
+			if tt.changeCondForNextSchedule == nil {
+				return
+			}
+			tt.changeCondForNextSchedule(tt)
+
+			// 3. schedule for the second time, and check whether second schedule result within tt.wants
+			got, err = g.assignReplicas(tt.clusters, tt.placement, tt.object)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("AssignReplicas() error = %v, wantErr %v", err, tt.wantErr)
 				return
 			}
-			for _, want := range tt.wants {
-				if helper.IsScheduleResultEqual(got, want) {
+			for _, secondScheduleResult = range tt.wants[firstScheduleResult] {
+				if isScheduleResultEqual(got, secondScheduleResult) {
 					return
 				}
 			}