Abstract: Plastic pre-strain test was carried out on servo hydraulic tensile testing machine for 304 austenitic stainless steel, then a new low temperature gaseous carburizing process for austenitic stainless steel was used. The residual stress analyzer, X-ray diffraction and ferrite measuring instrument were used to investigate the effect of pre-strain on low temperature gaseous carburization of 304 austenitic stainless steel. The results indicate that martensite transformation was present in 304 austenitic stainless steel after tensile deformation. The volume fraction of martensite increased with increase of deformation degree and it rised obviously when the pre-strain was more than 15%. The thickness of carburized layer was the same regardless of the deformation degree and martensite in carburized layer changed into expansion austenite (γ_C). The pre-strain did not affect the surface strengthening of low temperature gaseous carburization for 304 austenitic stainless steel.