Radiation creep and swelling of 16Cr-15Ni-3Mo-Nb steels were studied after irradiation in the BOR-60 reactor at 350 and 420 C up to maximum fluence 11.9*10²⁶ m^-2 (E>0.1MeV), i.e. 60 dpa. Pressurized tubes were made of two steels with different carbon content (0.046 and 0.006 w. %). Swelling of the stress-free tubes depends on carbon content. Radiation creep rate depends only upon the stress level and the rate of swelling. Coefficients of swelling and creep interrelation are not sensitive to carbon content and irradiation temperature.