diff --git a/db.go b/db.go
index 809fa60..28eba24 100644
--- a/db.go
+++ b/db.go
@@ -79,6 +79,27 @@ func (model *Model) AutoSave() bool {
 	return false
 }
 
+// DldCounter is used to validate duplicated download requests
+type DldCounter struct {
+	IPHistory map[string]time.Time
+}
+
+var DCounter DldCounter = DldCounter{}
+var DldInterval float64 = 60.0 // seconds
+
+func (counter *DldCounter) Validate(ip string) bool {
+	if counter.IPHistory == nil {
+		counter.IPHistory = make(map[string]time.Time)
+	}
+	if time.Since(counter.IPHistory[ip]).Seconds() > DldInterval {
+		counter.IPHistory[ip] = time.Now()
+		// fmt.Println("valid", ip)
+		return true
+	}
+	// fmt.Println("invalid", ip)
+	return false
+}
+
 // func main() {
 // 	filename := "./mydb.json"
 // 	DBModel.DBRead(filename)
diff --git a/httpstaticserver.go b/httpstaticserver.go
index a0393d9..db9663a 100644
--- a/httpstaticserver.go
+++ b/httpstaticserver.go
@@ -10,6 +10,7 @@ import (
 	"io/ioutil"
 	"log"
 	"mime"
+	"net"
 	"net/http"
 	"net/url"
 	"os"
@@ -126,7 +127,7 @@ func (s *HTTPStaticServer) hIndex(w http.ResponseWriter, r *http.Request) {
 		}
 		if r.FormValue("download") == "true" {
 			w.Header().Set("Content-Disposition", "attachment; filename="+strconv.Quote(filepath.Base(path)))
-			s.DBModel.Incre(path)
+			DldIncre(s.DBModel, r.RemoteAddr, path)
 		}
 		http.ServeFile(w, r, relPath)
 	}
@@ -289,7 +290,7 @@ func (s *HTTPStaticServer) hInfo(w http.ResponseWriter, r *http.Request) {
 
 func (s *HTTPStaticServer) hZip(w http.ResponseWriter, r *http.Request) {
 	path := mux.Vars(r)["path"]
-	s.DBModel.Incre(path)
+	DldIncre(s.DBModel, r.RemoteAddr, path)
 	CompressToZip(w, filepath.Join(s.Root, path))
 }
 
@@ -766,3 +767,10 @@ func checkFilename(name string) error {
 	}
 	return nil
 }
+
+func DldIncre(model Model, rAddress string, path string) {
+	ip, _, _ := net.SplitHostPort(rAddress)
+	if DCounter.Validate(ip) {
+		model.Incre(path)
+	}
+}