Laser processing was used to deposite TiCp/Ni Cr B Si C composite coatings on 45 # steel. The microstructure and wear properties were investigated by means of SEM, TEM, and wear test. The mechanism of surface modification of La 2O 3 on the composite coatings was also discussed. The results showed that TiC partly dissolved in the laser melt pool during melting. There were twins and dislocations at the interface of particle TiC and matrix due to the solidifying stress. The interdiffusion zone was formed between the coating and matrix. The carbides of (Fe,Cr) 23 C 6, the micro crystal of α and γ were discovered in the interdiffusion zone. The amorphous phase of Ni Si B La was formed at the interface. The wear resistance of coating was affected by rare earths and the content of TiC. The coatings possessed optimal wear resistance when the mass fraction of TiC was 45%～50%.