Timely adjusting the family planning policy is effective regulation for the population growth．At the end of 2013，China began to implement the “separate two children” policy，expected to stabilize the moderate low fertility，and promote longterm balanced development of the population．This paper takes sample data and field survey interviews to understand the influence of family planning policy on the fertility tendency and fertility of young couples in the cities．The results show that the contemporary urban youth couples have their contrary intentions because of the causes such as economic pressure, working pressure, lack of supporting policy, delayed marriage age and childbearing age, and intergroup conflict and so on. The fertility of the young couples in the cities needs to be transformed into reality by governments, society and families.