diff --git a/zsub/zsub.go b/zsub/zsub.go
index e2e49a4..5d83647 100644
--- a/zsub/zsub.go
+++ b/zsub/zsub.go
@@ -2,6 +2,7 @@ package zsub
 
 import (
 	"bufio"
+	"fmt"
 	"log"
 	"net"
 	"os"
@@ -369,8 +370,15 @@ func (s *ZSub) Publish(topic, msg string) {
 	if ztopic == nil {
 		return
 	}
-	ztopic.chMsg <- msg
 	ztopic.mcount++
+
+	// topic chan overload check
+	if len(ztopic.chMsg) == cap(ztopic.chMsg) {
+		log.Println(fmt.Sprintf("ztopic no cap: [%s %s]", topic, msg))
+		return
+	}
+
+	ztopic.chMsg <- msg
 }
 
 /*
diff --git a/zsub/ztopic.go b/zsub/ztopic.go
index c53c748..9b41eb4 100644
--- a/zsub/ztopic.go
+++ b/zsub/ztopic.go
@@ -1,6 +1,10 @@
 package zsub
 
-import "sync"
+import (
+	"fmt"
+	"log"
+	"sync"
+)
 
 type ZTopic struct { //ZTopic
 	sync.Mutex
@@ -19,7 +23,12 @@ func (t *ZTopic) init() {
 				break
 			}
 
-			for _, group := range t.groups {
+			for name, group := range t.groups {
+				// zgroup chan overload check
+				if len(group.chMsg) == cap(group.chMsg) {
+					log.Println(fmt.Sprintf("zgroup no cap: [%s.%s %s]", name, t.topic, msg))
+					continue
+				}
 				group.chMsg <- msg
 			}
 		}