SiC reinforced iron matrix composite coatings have been successfully produced by using a 2 kW Nd:YAG laser on a 40Cr steel substrate, and microstructure analysis and performance testing of the coatings are carried out. There are two forms of SiC in the experiment: particle and fiber. By adjusting the adding content of SiCp and of SiCf, evolution of SiC of different forms during laser cladding, existing forms of SiC in cladding layers and affection on hardness of cladding layers are studied. The results show that during laser cladding, SiC of different forms is decompounded partially; with the increasing of the SiC adding content, the quantity of un-melt SiC increases and hardness of cladding layers improves. Comparing the hardness of SiC particle reinforced coating with the SiC fiber reinforced coating, the reinforcing effecting of SiC fiber is higher; the main reasons bring hardness remarkable improvement are disperse reinforcement of un-melt SiC and propitiation FeSiC, and solution reinforcement of decompounded Si, C.