One 2 kW high power diode laser was used for cladding of high speed steel powder on the substrate of a tool steel. A crackfree cladding layer could be obtained along the interacted zone of the focused powder stream and focused laser beam. With the increasing of laser power, the thickness of cladding and availability of powder were increased, and the dilution of substrate to cladding layer was decreased. The hardness of the cladding layer was up to 800 Hv0.3 and the hardness of the substrate was up to 200 Hv0.3. The result demonstrates that high power diode laser is very competitive for future application in surface cladding