Laser welding of dissimilar metals has been widely used to improve a wear resistance and a corrosion resistance of the industrial parts. The objective of this research is to investigate the influence of the process parameters, such as the welding for SM45C and STS304 with CW Nd:YAG lasers. The bead-on-plate welding tests arc carried out for several combinations of the experimental conditions. In order to quantitatively examine the characteristics of the dissimilar welding, the welding quality of the cut section, stress-strain behavior and the hardness of the welded metal are investigated. From the results of the investigation, it has been shown that the optimal welding condition without defects in the vicinity of the welded area and with a good welding quality is l600W of the laser power, 0.85m/min of welding speed and 4ℓ/min of pressure for shielding gas.