In this paper,the experimental metho d are presented for laser cladding monel and rare earth and ceramic alloy coating s on the 45 # steel surface using a transverse-flow CO 2 laser with an output power of 2 kW.By using HX-1000 micro-hardness tester,we also ta ke an observation and analysis about the micro-hardness variety of laser claddi ng layer and microstructure of the transition region between substrate and coati ng.The results indicate that the rare earth and ceramic materials essentially ch ange the chemical composition and microstructure of surface layer,the metallurgy bond intensity is basically improved.This results have important significance f or practical application.