diff --git a/docs/坦克大战笔记.docx b/docs/坦克大战笔记.docx
index d8fa2c4..c958764 100644
Binary files a/docs/坦克大战笔记.docx and b/docs/坦克大战笔记.docx differ
diff --git a/src/com/demo/tank/course3/Bullet.java b/src/com/demo/tank/course3/Bullet.java
index 70f708f..6f1f7d4 100644
--- a/src/com/demo/tank/course3/Bullet.java
+++ b/src/com/demo/tank/course3/Bullet.java
@@ -6,8 +6,8 @@ public class Bullet {
     private int x, y;
     private Direction direction;
     private static final int SPEED = 5;
-    private static final int WIDTH = 20;
-    private static final int HEIGHT = 20;
+    public static final int WIDTH = ResourceManager.bulletD.getWidth();
+    public static final int HEIGHT = ResourceManager.bulletD.getHeight();
     private boolean live = true;
     private TankFrameV3 tf;
 
@@ -22,10 +22,20 @@ public class Bullet {
         if(!live){
             tf.bullets.remove(this);
         }
-        Color color = g.getColor();
-        g.setColor(Color.RED);
-        g.fillOval(x, y, WIDTH, HEIGHT);
-        g.setColor(color);
+        switch (direction){
+            case UP:
+                g.drawImage(ResourceManager.bulletU, x, y, null);
+                break;
+            case DOWN:
+                g.drawImage(ResourceManager.bulletD, x, y, null);
+                break;
+            case LEFT:
+                g.drawImage(ResourceManager.bulletL, x, y, null);
+                break;
+            case RIGHT:
+                g.drawImage(ResourceManager.bulletR, x, y, null);
+                break;
+        }
         move();
     }
 
diff --git a/src/com/demo/tank/course3/ResourceManager.java b/src/com/demo/tank/course3/ResourceManager.java
index db7228d..e981221 100644
--- a/src/com/demo/tank/course3/ResourceManager.java
+++ b/src/com/demo/tank/course3/ResourceManager.java
@@ -6,6 +6,7 @@ import java.io.IOException;
 
 public class ResourceManager {
     public static BufferedImage tankL, tankR, tankU, tankD;
+    public static BufferedImage bulletL, bulletR, bulletU, bulletD;
 
     static {
         try {
@@ -13,6 +14,11 @@ public class ResourceManager {
             tankR = ImageIO.read(ResourceManager.class.getClassLoader().getResourceAsStream("com/demo/tank/images/tankR.gif"));
             tankU = ImageIO.read(ResourceManager.class.getClassLoader().getResourceAsStream("com/demo/tank/images/tankU.gif"));
             tankD = ImageIO.read(ResourceManager.class.getClassLoader().getResourceAsStream("com/demo/tank/images/tankD.gif"));
+
+            bulletL = ImageIO.read(ResourceManager.class.getClassLoader().getResourceAsStream("com/demo/tank/images/bulletL.gif"));
+            bulletR = ImageIO.read(ResourceManager.class.getClassLoader().getResourceAsStream("com/demo/tank/images/bulletR.gif"));
+            bulletU = ImageIO.read(ResourceManager.class.getClassLoader().getResourceAsStream("com/demo/tank/images/bulletU.gif"));
+            bulletD = ImageIO.read(ResourceManager.class.getClassLoader().getResourceAsStream("com/demo/tank/images/bulletD.gif"));
         } catch (IOException e) {
             e.printStackTrace();
         }
diff --git a/src/com/demo/tank/course3/Tank.java b/src/com/demo/tank/course3/Tank.java
index 6db57e1..7ba28b3 100644
--- a/src/com/demo/tank/course3/Tank.java
+++ b/src/com/demo/tank/course3/Tank.java
@@ -8,6 +8,8 @@ public class Tank {
     private static final int SPEED = 10;
     private boolean moving;
     private TankFrameV3 tankFrame;
+    public static final int WIDTH = ResourceManager.tankD.getWidth();
+    public static final int HEIGHT = ResourceManager.tankD.getHeight();
 
 
     public Tank(int x, int y, Direction dir, TankFrameV3 tankFrame) {
@@ -86,6 +88,8 @@ public class Tank {
     }
 
     public void fire() {
-        tankFrame.bullets.add(new Bullet(x, y, this.dir, tankFrame));
+        int bx = x + Tank.WIDTH/2 - Bullet.WIDTH/2;
+        int by = y + Tank.HEIGHT/2 - Bullet.HEIGHT/2;
+        tankFrame.bullets.add(new Bullet(bx, by, this.dir, tankFrame));
     }
 }