Abstract: The neutron in the pressure water reactor (PWR) core scatters on the hydrogen nuclei of primary coolant to produce the energetic proton, then proton reacts with the target nuclei in primary coolant to produce radionuclide. In this paper we take the Qinshan second periodic pressure water reactor as a sample: first, calculate the high energy neutron flux and obtain the proton spectrum;then,calculate the productive rate of the radionuclides,which are 13 N produced by 16 O (p,α) 13 N reaction, 18 F produced by 18 O(p,n) 18 F reaction, 11 C produced by 11 B(p,n) 11 C reaction; final, according to the circulation character of primary circuit water, obtain the specific radioactivities of these radionuclides.