diff --git a/Lesson2/hw-2.sol b/Lesson2/hw-2.sol
new file mode 100644
index 000000000..99ec61f12
--- /dev/null
+++ b/Lesson2/hw-2.sol
@@ -0,0 +1,95 @@
+pragma solidity ^0.4.14;
+
+contract payRoll{
+    struct Employee {
+        address id;
+        uint salary;
+        uint lastPayday;
+    }
+    
+    uint constant payDuration = 10 seconds;
+    
+    address owner;
+    Employee[] employees;
+    
+    function Payroll(){
+        owner = msg.sender;
+    }
+    
+    function _partialPaid(Employee employee) private {
+        uint payment = employee.salary * (now - employee.lastPayday) / payDuration;
+        employee.id.transfer(payment);
+    }
+    
+    function _findEmployee(address employeeId) private returns (Employee, uint){
+        for(uint i=0; i<employees.length;i++){
+            if(employees[i].id == employeeId){
+                return (employees[i], i);
+            }
+        }         
+    }
+    
+    function addEmployee(address employeeId, uint salary){
+        require(msg.sender == owner);
+        
+        var (employee, index) = _findEmployee(employeeId);
+        assert(employee.id == 0x0);
+        
+        employees.push(Employee(employeeId, salary, now));
+    }
+    
+    function removeEmployee(address employeeId){
+        require(msg.sender == owner);
+        
+        var (employee, index) = _findEmployee(employeeId);
+        
+        assert(employee.id == 0x0);
+        _partialPaid(employee);
+        
+        delete employees[index];
+        employees[index] = employees[employees.length -1];
+        employees.length -= 1;
+        
+    }
+    
+    function updateEmployee(address employeeId, uint salary) {
+        require(msg.sender == owner);
+        
+        var (employee, index) = _findEmployee(employeeId);
+        
+        assert(employee.id == 0x0);
+        _partialPaid(employee);
+        employees[index].salary = salary;
+        employees[index].lastPayday = now;
+        
+    }
+    
+    function addFund() returns (uint) {
+        return this.balance;
+    }
+    
+    function calculateRunway() returns (uint) {
+        uint totalSalary = 0;
+        for(uint i=0; i<employees.length;i++){
+            totalSalary += employees[i].salary;
+        }
+        return this.balance / totalSalary;
+    }
+    
+    function hasEnoughFund() returns (bool) {
+        return calculateRunway() > 0;
+    }
+    
+    function getPaid() {
+        var (employee, index) = _findEmployee(msg.sender);
+        assert(employee.id == 0x0);
+        
+        
+        uint nextPayday = employee.lastPayday + payDuration;
+        assert(nextPayday < now);
+        
+        employees[index].lastPayday = nextPayday;
+        employees[index].id.transfer(employee.salary);
+    }
+    
+}
\ No newline at end of file
diff --git a/Lesson3/assignment/yours.sol b/Lesson3/assignment/yours.sol
index dfdb2c486..189a9cd28 100644
--- a/Lesson3/assignment/yours.sol
+++ b/Lesson3/assignment/yours.sol
@@ -1 +1,104 @@
 /*作业请提交在这个目录下*/
+
+//q1
+
+pragma solidity ^0.4.14;
+
+contract payRoll{
+    struct Employee {
+        address id;
+        uint salary;
+        uint lastPayday;
+    }
+    
+    uint constant payDuration = 10 seconds;
+    
+    address owner;
+    uint totalSalary;
+    mapping(address => Employee) employees;
+    
+    function Payroll(){
+        owner = msg.sender;
+    }
+    
+    function _partialPaid(Employee employee) private {
+        uint payment = employee.salary * (now - employee.lastPayday) / payDuration;
+        employee.id.transfer(payment);
+    }
+    
+    function addEmployee(address employeeId, uint salary){
+        require(msg.sender == owner);
+        
+        var employee = employees[employeeId];
+        assert(employee.id == 0x0);
+        totalSalary += salary * 1 ether;
+        employees[employeeId] = (Employee(employeeId, salary * 1 ether, now));
+    }
+    
+    function removeEmployee(address employeeId){
+        require(msg.sender == owner);
+        
+        var employee = employees[employeeId];
+        
+        assert(employee.id == 0x0);
+        _partialPaid(employee);
+        totalSalary -= employees[employeeId].salary;
+        delete employees[employeeId];
+        
+    }
+    
+    function updateEmployee(address employeeId, uint salary) {
+        require(msg.sender == owner);
+        
+        var employee = employees[employeeId];
+        
+        assert(employee.id == 0x0);
+        _partialPaid(employee);
+        totalSalary -= employees[employeeId].salary;
+        employees[employeeId].salary = salary;
+        employees[employeeId].lastPayday = now;
+        totalSalary += employees[employeeId].salary;
+        
+    }
+    
+    function addFund() returns (uint) {
+        return this.balance;
+    }
+    
+    function calculateRunway() returns (uint) {
+        return this.balance / totalSalary;
+    }
+    
+    function hasEnoughFund() returns (bool) {
+        return calculateRunway() > 0;
+    }
+    
+    function checckEmployee(address employeeId) returns (uint salary, uint lastPayday){
+        var employee = employees[employeeId];
+        salary = employee.salary;
+        lastPayday = employee.lastPayday;
+    }
+    
+    function getPaid() {
+        var employee = employees[msg.sender];
+        assert(employee.id == 0x0);
+        
+        
+        uint nextPayday = employee.lastPayday + payDuration;
+        assert(nextPayday < now);
+        
+        employee.lastPayday = nextPayday;
+        employee.id.transfer(employee.salary);
+    }
+    
+}
+
+
+/// q2
+function changePaymentAddress(address employeeId, address newEmployeeId) onlyOwner employeeExist(employeeId) {
+  var employee = employees[employeeId];
+  
+  _partialPaid(employee);
+  employees[employeeId].id = newEmployeeId;
+  employees[newEmployeeId].lastPayday = now;
+}
diff --git a/lesson1/hw-1.sol b/lesson1/hw-1.sol
new file mode 100644
index 000000000..455d868ab
--- /dev/null
+++ b/lesson1/hw-1.sol
@@ -0,0 +1,38 @@
+pragma solidity ^0.4.14;
+
+contract payRoll{
+    uint salary = 1 ether;
+    address wallet;
+    uint constant payDuration = 30 days;
+    uint lastPayday = now;
+    
+    function getWallet() {
+        wallet = msg.sender;
+    }
+    
+    function addFund() returns (uint) {
+        return this.balance;
+    }
+    
+    function calculateRunway() returns (uint) {
+        return this.balance / salary;
+    }
+    
+    function hasEnoughFund() returns (bool) {
+        return calculateRunway() > 0;
+    }
+    
+    function getPaid() {
+        if(msg.sender != wallet){
+            revert();
+        }
+        
+        uint nextPayday = lastPayday + payDuration;
+        if(nextPayday > now){
+            revert();
+        }
+        lastPayday = nextPayday;
+        wallet.transfer(salary);
+    }
+    
+}
\ No newline at end of file
diff --git "a/\343\200\220\346\265\213\350\257\225\343\200\221\347\254\254\344\270\200\350\257\276\344\275\234\344\270\232" "b/\343\200\220\346\265\213\350\257\225\343\200\221\347\254\254\344\270\200\350\257\276\344\275\234\344\270\232"
new file mode 100644
index 000000000..f0ce4777d
--- /dev/null
+++ "b/\343\200\220\346\265\213\350\257\225\343\200\221\347\254\254\344\270\200\350\257\276\344\275\234\344\270\232"
@@ -0,0 +1 @@
+测试·第一课作业