In order to investigate the inelastic deformation behavior of stainless steel beams, 4 stainless steel welded beams under pure bending and concentrated load were performed in this paper. The grade of stainless steel was approximately equivalent to UNS S31600. The relationship between load and deflection was discussed and the comparison between experimental results and results obtained by different methods, including finite element analysis method, simplified method proposed by Pro. Wang, Pro. E Real and EN 1993-1-4 Eurocode 3. The results showed that the deformation behavior of stainless steel performed non-linear load- deflection relationship because of the influence of nonlinear material properties. The deflections obtained by those methods were lower than the experimental results.