Abstract: Both from experiments and theoretical analysis,the influenceof laser processing parameters on the case-depth and the hardness in laser quenching was studied.Under the condition of equal input laser energyand different laser power and scanning velocity,the variation of the case-depth and the hardness was measured.Measurement results show that the change of both the laser power and the scanning velocity can affect the case-depth and the hardness obviously and the change of laser power affects the case-depth more significantly.On the other hand,the change of either the laser power or the scanning velocity has a little influence on the hardness.Correspondingly,the change of the scanning velocity has a little more influence on the hardness.By means of analytical simulation of the temperature distribution and the heating/cooling rates under the laser scanning,reasonable explanation for the results was put forward.