Abstract: In order to study effect of femtosecond laser pulse energy on the periodic structure of stainless steel surface, the femtosecond laser with pulse width of 50fs and central wavelength of 800nm was used to radiate 304 stainless steel surfaces. Scanning electron microscopy was used to observe the micromorphology and the generation mechanism of different kinds of ripples was analyzed. The results show that with pulse energy from 0.1mJ to 0.3mJ, nanoscale periodic ripple perpendicular to the direction of laser polarization is formed on the surface. With pulse energy from 0.4mJ to 0.7mJ, there is a tendency to produce periodic ripples parallel to the direction of laser polarization. With pulse energy from 0.8mJ to 1.0mJ, obvious micron-scale periodic corrugation parallel to the polarization direction of laser appears on the surface, and the corrugation surface is covered with short periodic corrugation perpendicular to its direction. The study lays the foundation for the subsequent preparation of controllable micromorphology on the surface of stainless steel.