Abstract: A single-pass welded joint of 10 mm thick 304 stainless steel was prepared under two different high power laser powers of 9 kW and 9. 5 kW. The microstructure of the sample was observed by optical microscopy and scanning electron microscopy. The microhardness of the welded samples was tested by microhardness tester. The electrochemical characteristics of the welding samples in different solutions were tested by electrochemical tests,and the electrochemical characteristics of the welded joints in 3. 5 wt% NaCl solution were further tested. Comprehensive analysis results showed that the microhardness of the welded joints was similar. The microstructure of the 9. 5 kW laser power sample was more uniform,whose corrosion resistance was stronger in 3. 5 wt% NaCl and weaker in 10 wt% HCl solution. Both the samples had good corrosion resistance in 10 wt% NaO H solution. The SVET results indicated that the two samples owned similar variation trend with increasing of immersion time.