The characteristic of pulsed laser welding process of small - size stainless steel sheets is studied and how welding parameters affect the penetration status and the width of welding line is specially analyzed. Experimental results show that the penetration threshold of laser power density decreases and the one of laser average power increases with the increment of pulse time, but laser power density cannot be always reduced, it must maintain above a certain limit to ensure the penetration. The parameters , which significantly affect the width of welding line, are laser power density, pulse time and frequency. This paper not only offers some useful experience for precise laser welding of small - size workpieces whose condition of heat transferring is limited, but also establishes experimental foundation for numerical simulation analysis of the welding process using Finite Element Method.