Abstract: The effects of the processing parameters of powder feeding laser cladding on the dilution of the Ni60A coatings were studied systematically.In order to explain the relationship between the powder feeding rate,scanning speed and the dilution,the concepts of the specific energy input E_r and the specific energy E_h formulated by L.C.Lim were introduced with their experimental measuring methods which have been proved successful.By varying the powder feeding rate and scanning speed under definite laser powder P and beam spot dimensions,coatings with different thickness were obtained.The calculation of the specific energy input E_r and the specific energy E_h was carried out on metallographical measurement.The explanation was given on the relationship between the processing parameters and the dilution.With the increasement of the powder feeding rate and scanning speed,the dilution becomes smaller.In the meantime,it is the theoretical foundation for further study on the relationship between the microstructure,mechanism of solidification and the processing parameters.