Nowadays many post-employment restraint agreements don't appoint to pay compensation for the labour,but arrange the penalty liability when the labour infringes the obligation of post-employment restraint.There are serious disagreements on the legal force of the penalty clause.Our current laws don't make definite provisions on this matter,and some local places produce different specification for executing the law,so it contributes to sharp differences of legal decision in judicial practice.From angles of the quality of contract rights,the legal position of the parties and that laws maintaining the substantive justice of the contract,post-employment restraint agreement should be invalid and the duty of penalty have not legal effect also.The post-employment restraint agreements already appoint compensation,almost at the same time arrange the penalty when the labour infringes the obligation of post-employment restraint.Pay less compensation for the labour and at the same time demand huge penalty when the labour breaks the contract.Thus the point at this issue is that how we can handle the penalty.On this matter,we should remedy the shortcoming in legislation,make it clearly that the post-employment restraint agreement is invalid when there is no compensation clause,as to arranging the compensation number already,it should put forward the mandatory demands of compensation number and clarify the conditions that the penalty can be revised.