diff --git a/internal/rootcoord/root_coord.go b/internal/rootcoord/root_coord.go
index 7405ac3d94..c07b945f12 100644
--- a/internal/rootcoord/root_coord.go
+++ b/internal/rootcoord/root_coord.go
@@ -978,7 +978,6 @@ func (c *Core) CreateCollection(ctx context.Context, in *milvuspb.CreateCollecti
 
 	metrics.RootCoordDDLReqCounter.WithLabelValues("CreateCollection", metrics.SuccessLabel).Inc()
 	metrics.RootCoordDDLReqLatency.WithLabelValues("CreateCollection").Observe(float64(tr.ElapseSpan().Milliseconds()))
-	metrics.RootCoordNumOfCollections.Inc()
 	metrics.RootCoordDDLReqLatencyInQueue.WithLabelValues("CreateCollection").Observe(float64(t.queueDur.Milliseconds()))
 
 	log.Ctx(ctx).Info("done to create collection",
@@ -1028,7 +1027,6 @@ func (c *Core) DropCollection(ctx context.Context, in *milvuspb.DropCollectionRe
 
 	metrics.RootCoordDDLReqCounter.WithLabelValues("DropCollection", metrics.SuccessLabel).Inc()
 	metrics.RootCoordDDLReqLatency.WithLabelValues("DropCollection").Observe(float64(tr.ElapseSpan().Milliseconds()))
-	metrics.RootCoordNumOfCollections.Dec()
 	metrics.RootCoordDDLReqLatencyInQueue.WithLabelValues("DropCollection").Observe(float64(t.queueDur.Milliseconds()))
 
 	log.Ctx(ctx).Info("done to drop collection", zap.String("role", typeutil.RootCoordRole),
@@ -1279,7 +1277,6 @@ func (c *Core) AlterCollection(ctx context.Context, in *milvuspb.AlterCollection
 
 	metrics.RootCoordDDLReqCounter.WithLabelValues("AlterCollection", metrics.SuccessLabel).Inc()
 	metrics.RootCoordDDLReqLatency.WithLabelValues("AlterCollection").Observe(float64(tr.ElapseSpan().Milliseconds()))
-	metrics.RootCoordNumOfCollections.Dec()
 	metrics.RootCoordDDLReqLatencyInQueue.WithLabelValues("AlterCollection").Observe(float64(t.queueDur.Milliseconds()))
 
 	log.Info("done to alter collection",