Based on the multi-configuration Dirac-Fock method, 2p photoionization process of sodium atoms from the initial state 2p63p were investigated at a photon energy of 54 eV. Usually the relativistic effect has very obvious influence on atomic photoionization process. The influence of relativistic effects on the photoionization thresholds is negligible, but it can produce substantial change in the intensity distribution in photoelectron spectra, so that the spectra structures from the initial states 2p63p(2P1/2,3/2) are completely different. In the nonrelativistic limit, as generally expected, the spectra structures from the two states are almost identical. Furthermore, this study demonstrates the information that may be obtained regarding the relativistic effects in the photoionization processes from excited states.