diff --git a/src/main/java/org/ntlab/acanthus_server/entities/Stroke.java b/src/main/java/org/ntlab/acanthus_server/entities/Stroke.java
index 140d96d..4900751 100644
--- a/src/main/java/org/ntlab/acanthus_server/entities/Stroke.java
+++ b/src/main/java/org/ntlab/acanthus_server/entities/Stroke.java
@@ -6,11 +6,16 @@
 import org.ntlab.acanthus_server.entities.Position;
 
 public class Stroke {
+    private static int i; //strokeNoを数えるためだけ
+    private int strokeNo;
     private int pen;
     private int color;
     private int thickness;
     private ArrayList<Position> positions = new ArrayList<>();
 
+    public int getStrokeNo() {
+        return this.strokeNo;
+    }
     public int getPen() {
         return this.pen;
     }
@@ -21,7 +26,13 @@
         return this.thickness;
     }
 
-    public void setStrokes(int pen, int color, int thickness) {
+    //書き始めたらstrokeNoを追加する。
+    public void addStrokeNo(){
+        this.i++;
+        this.strokeNo = i;
+}
+
+    public void addStrokes(int pen, int color, int thickness) {
         this.pen = pen;
         this.color = color;
         this.thickness = thickness;