High-strength steel E36 and stainless steel 304 are welded by laser welding with the same line energy. Microstructure and fracture morphology of welded joint are investigated by means of optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD), and the mechanical properties of the weld are evaluated by micro-hardness and tensile strength testing. The results show that both heat input and laser power density play a crucial role in macro-morphology of welded joint. Welding speed has a significant impact on micro grain morphology. Weld zone is made up of martensite and some carbide particles. There are mainly austenites and a bit δ -ferrites on the 304 fusion zone while lath-shaped martensite, bainite and ferrites are produced on the heat affected zone of E36. When the laser power is 1 kW, micro-hardness of the welding seam is lower than that of the others, and the tensile specimen break occurs at the seam, while the other specimens occur at the side of E36.