Abstract: In the latest design of PWR fuel assemblies, urania-gadolinia (UO₂-Gd₂O₃) fuel is widely adopted as burnable poison to control the initial reactivity and flatten the power profile in reactor. And the performance of gadolinia doped fuel rods is different from ordinary fuel rods. In this study, the performance of gadolinia doped fuel rods, which were tested in BR3 reactor, was analyzed by using the fuel performance code FRAPCON-3.5. The results show that the calculated values agree with the experiment values. In addition, the self-shielding effect of gadolinia doped fuel rods is enhanced at the initial period of radiation, which has a significant influence on the radial power distribution of fuel rods. Besides, if the average power density is same, the thermal conductivity of gadolinia doped fuel is lower which results in higher pellet temperature. The fission gas release fraction and the deformations of fuel and cladding are different with the weight fraction of gadolinia in fuel.