Obviously, the two lifecycle in the software project management is closely related. Risk management aims at software project. Thus the tasks of each stage in the lifecycle of software project decide the ones of risk management. The end of software project lifecycle indicates the end of lifecycle of risk management. The risk management cycle also affects the process of software project. Firstly, the risk management is a part of software project management. Each stage ends with all of its work including stage risk management finished. Secondly, if some stage in the project was in a low-risk state, the project will be well into its next stage, i.e. the condition of entering other stage is that the risks are properly controlled in last stage. Vice versa, active risk-response measures should be taken, so the process into next stage is slowed down. Therefore, these two lifecycles are complementary.