The problems occurring in the fission product source term calculations for M310/CPR1000, EPR and AP1000 are briefly analyzed, based on the related regulations and standards, as well as operational feedback, review experiences and recent research achievements for nuclear power plants in China. The framework of fission product source term proper to China has been first studied and proposed in perspective of the purpose of source terms. The calculation processes of fission product source term are rearranged and the requirements for deferent reactor types are specified. The proposed framework can be taken as a foundation for solution of the long-standing problems in the calculation of fission product source term and provide reference for source term calculation.