High current pulsed electron beam has been developing as a useful tool for surface modification of materials. This paper presents our research on the surface treatment of 316L stainless steel with an equipment of working parameters as electron energy 20-30keV, pulse duration 1.5µs and energy density ~6J/cm2. The surface microstructure was characterized with metallography, X-ray diffractometry and electron backscatter diffraction (EBSD) techniques. It was found that the modified samples showed significant improvement on corrosion resistance when using increased pulse number and higher energy density. This result is discussed in relation to the coupled temperature-stress fields formed after the absorption of electron beam energy.