Abstract: The quality of pulsed Nd:YAG laser cladding depends on the voltage, electric current, pulse length, pulse frequency, scanning speed, and beam diameter of the Nd:YAG laser. In order to fully conside the effect of these processing parameters and simplify the processes, spot overlap definition is referred. With the help of theoretic analysis, the relationship between spot overlap and three parameters (the pulse frequency, the scanning speed and the beam diameter of the Nd:YAG laser) is formulated. The experiment, which is based on lower carbon steel, is carried out with precoated layer by laser cladding Ni-base alloy. The perfect processing parameters are available,with single pulsed energy and spot overlap separately 6.7 J and 97.4% or 21 J and 69.4%.