diff --git a/day09/src/com/inmind/extends_constructor04/Demo05.java b/day09/src/com/inmind/extends_constructor04/Demo05.java
new file mode 100644
index 0000000..c2be63e
--- /dev/null
+++ b/day09/src/com/inmind/extends_constructor04/Demo05.java
@@ -0,0 +1,17 @@
+package com.inmind.extends_constructor04;
+/*
+继承中构造方法的访问特点
+1.创建子类对象时，一定会调用父类的构造方法
+2.super调用父类的构造方法时，必须在子类的构造方法的第一行
+3.super可以调用父类的有参构造方法。
+ */
+public class Demo05 {
+    public static void main(String[] args) {
+        //创建子类对象
+        Zi zi = new Zi();
+        //创建父类对象
+        Fu fu = new Fu(10);
+
+        System.out.println("程序结束");
+    }
+}
diff --git a/day09/src/com/inmind/extends_constructor04/Fu.java b/day09/src/com/inmind/extends_constructor04/Fu.java
new file mode 100644
index 0000000..f69f3b8
--- /dev/null
+++ b/day09/src/com/inmind/extends_constructor04/Fu.java
@@ -0,0 +1,16 @@
+package com.inmind.extends_constructor04;
+
+public class Fu {
+    int num;
+
+    //父类的无参构造方法
+    public Fu(){
+        System.out.println("父类无参构造方法");
+    }
+
+    //父类的有参构造方法
+    public Fu(int num){
+        System.out.println("父类有参构造方法");
+        this.num = num;
+    }
+}
diff --git a/day09/src/com/inmind/extends_constructor04/Zi.java b/day09/src/com/inmind/extends_constructor04/Zi.java
new file mode 100644
index 0000000..15c63b9
--- /dev/null
+++ b/day09/src/com/inmind/extends_constructor04/Zi.java
@@ -0,0 +1,9 @@
+package com.inmind.extends_constructor04;
+
+public class Zi extends Fu{//子类继承了父类，拥有了父类的非私有的成员
+
+    public Zi(){
+        //super(10);//注意：如果不写该行代码，编译器会自动添加super()，调用父类的无参构造，并且必须在第一行
+        System.out.println("子类的无参构造方法");
+    }
+}