Abstract: In order to research the thermal-mechanical response of single fuel rod under accident conditions, fuel transient performance analysis code FTPAC was developed, which mainly consisted of temperature, mechanical deformation, gas pressure and cladding oxidation models. The FTPAC was evaluated by the standard example problem of FRAP-T6 code, and four test fuel rods for NSRR and CABIR were calculated by using FTPAC. The results show that FTPAC provides reasonable predictions of non-failure fuel rod response during transient conditions.