diff --git a/ledis/t_zset.go b/ledis/t_zset.go
index f039487..fc86248 100644
--- a/ledis/t_zset.go
+++ b/ledis/t_zset.go
@@ -939,7 +939,6 @@ func (db *DB) ZUnionStore(destKey []byte, srcKeys [][]byte, weights []int64, agg
 
 func (db *DB) ZInterStore(destKey []byte, srcKeys [][]byte, weights []int64, aggregate byte) (int64, error) {
 
-	var destMap = map[string]int64{}
 	aggregateFunc := getAggregateFunc(aggregate)
 	if aggregateFunc == nil {
 		return 0, errInvalidAggregate
@@ -958,20 +957,27 @@ func (db *DB) ZInterStore(destKey []byte, srcKeys [][]byte, weights []int64, agg
 		}
 	}
 
-	var keptMembers [][]byte
-	for i, key := range srcKeys {
+	var destMap = map[string]int64{}
+	scorePairs, err := db.ZRange(srcKeys[0], 0, -1)
+	if err != nil {
+		return 0, err
+	}
+	for _, pair := range scorePairs {
+		destMap[String(pair.Member)] = pair.Score * weights[0]
+	}
+
+	for i, key := range srcKeys[1:] {
 		scorePairs, err := db.ZRange(key, 0, -1)
 		if err != nil {
 			return 0, err
 		}
+		tmpMap := map[string]int64{}
 		for _, pair := range scorePairs {
-			if score, ok := destMap[String(pair.Member)]; !ok {
-				destMap[String(pair.Member)] = pair.Score * weights[i]
-			} else {
-				keptMembers = append(keptMembers, pair.Member)
-				destMap[String(pair.Member)] = aggregateFunc(score, pair.Score*weights[i])
+			if score, ok := destMap[String(pair.Member)]; ok {
+				tmpMap[String(pair.Member)] = aggregateFunc(score, pair.Score*weights[i+1])
 			}
 		}
+		destMap = tmpMap
 	}
 
 	t := db.zsetTx
@@ -981,13 +987,12 @@ func (db *DB) ZInterStore(destKey []byte, srcKeys [][]byte, weights []int64, agg
 	db.zDelete(t, destKey)
 
 	var num int64 = 0
-	for _, member := range keptMembers {
-		score := destMap[String(member)]
-		if err := checkZSetKMSize(destKey, member); err != nil {
+	for member, score := range destMap {
+		if err := checkZSetKMSize(destKey, []byte(member)); err != nil {
 			return 0, err
 		}
 
-		if n, err := db.zSetItem(t, destKey, score, member); err != nil {
+		if n, err := db.zSetItem(t, destKey, score, []byte(member)); err != nil {
 			return 0, err
 		} else if n == 0 {
 			//add new
@@ -1002,7 +1007,7 @@ func (db *DB) ZInterStore(destKey []byte, srcKeys [][]byte, weights []int64, agg
 	if err := t.Commit(); err != nil {
 		return 0, err
 	}
-	return int64(len(keptMembers)), nil
+	return int64(len(destMap)), nil
 }
 
 func (db *DB) ZScan(key []byte, count int, inclusive bool) ([][]byte, error) {
diff --git a/server/cmd_zset_test.go b/server/cmd_zset_test.go
index e6a6a70..8c74bdc 100644
--- a/server/cmd_zset_test.go
+++ b/server/cmd_zset_test.go
@@ -704,4 +704,36 @@ func TestZInterStore(t *testing.T) {
 			t.Fatal("invalid value ", n)
 		}
 	}
+
+	if _, err := c.Do("zadd", "k3", "3", "three"); err != nil {
+		t.Fatal(err.Error())
+	}
+
+	if n, err := ledis.Int64(c.Do("zinterstore", "out", "3", "k1", "k2", "k3", "aggregate", "sum")); err != nil {
+		t.Fatal(err.Error())
+	} else {
+		if n != 0 {
+			t.Fatal("invalid value ", n)
+		}
+	}
+
+	if _, err := c.Do("zadd", "k3", "3", "two"); err != nil {
+		t.Fatal(err.Error())
+	}
+
+	if n, err := ledis.Int64(c.Do("zinterstore", "out", "3", "k1", "k2", "k3", "aggregate", "sum", "weights", "3", "2", "2")); err != nil {
+		t.Fatal(err.Error())
+	} else {
+		if n != 1 {
+			t.Fatal("invalid value ", n)
+		}
+	}
+
+	if n, err := ledis.Int64(c.Do("zscore", "out", "two")); err != nil {
+		t.Fatal(err.Error())
+	} else {
+		if n != 14 {
+			t.Fatal("invalid value ", n)
+		}
+	}
 }