Eight specimens were tested under pure bending to investigate the overall buckling behavior of stainless steel welded I-beams, and the main parameter varied in experimental study was slenderness ratio. The test specimens were fabricated from cold rolled plate of austenitic stainless steel type 316. The material properties were determined by tensile coupon tests. A non-linear finite element model is developed and verified against test results. Initial imperfection and material non-linearities were included in the finite element model. In addition, the buckling strength of test specimens were compared with the design method proposed in the previous research. It is shown that the finite element model closely predicted the overall buckling strength and load-deformation curves; the design method was proved to be safe.