In order to increase the welding yield,the property and the life of semiconductor laser,thick Au films were deposited on the P side of semiconductor laser chip by pulse electroplating technology.The effects of pH and on/off ratio of gold plating liquid on the morphology,surface roughness,intrinsic stress,uniformity and adhesion of the Au films were studied comprehensively.The results show that the surface roughness increases with the increase of pH or on/off ratio.The deposition uniformity firstly decreases then increases with the pH increasing from 8.0 to 10.0,while becomes worse with the increase of on/off ratio.The adhesions between the Au films and laser chips are not excellent when the pH is too high(> 10.0) or too low(< 8.5).However,the on/off ratio has a weak effect on the adhesion of Au films.The intrinsic stresses of Au films platted under different conditions are tensile with the range from 29 to 88 MPa.