diff --git a/sys.h b/sys.h
new file mode 100644
index 0000000..e98db26
--- /dev/null
+++ b/sys.h
@@ -0,0 +1,37 @@
+#define  _CRT_SECURE_NO_WARNINGS
+#include<stdio.h>
+#include<stdlib.h>
+#include<string.h>
+#define maxsize 50
+
+typedef struct
+{
+	char names[maxsize];
+	int num;
+	int math;
+	int english;
+	int sum_score;
+}student;
+
+
+
+
+typedef struct LNode
+{
+	student data;
+	struct LNode* next;
+}LNode;
+
+
+
+
+void studentinit(student t);
+int student_show_menu();
+void student_show(LNode* head); //读取全部学生信息
+void student_input(LNode* head); //输入学生信息
+int name_find(LNode* head, student f); //按姓名查询学生
+int num_find(LNode* head, student f2); //按学号查找学生
+void num_seq(LNode* head); //按学号排序
+void sum_seq(LNode* head); //按总成绩排序
+void stu_insert(LNode* head, student in); //增加学生信息
+void stu_del(LNode* head, student* dl); //删除学生信息