TiC particle reinforced iron based composite coating were in situ synthesized on surface of Q235 steel by Submerged-arc Welding (SAW) using the mixture consisted of ferrotitanium, ferrochromium, iron and carbon powders. Microstructure of the coating was observed by scanning electron microscope（SEM）and X-ray diffraction(XRD). Microhardness was measured by microhardness tester. Results indicated that the fine TiC particles were formed by using SAW process and dispersed in the matrix. And the particles sizes were less than 2μm. Microstructure of coating consists of TiC particles, martensite and austenite. The microhardness of coating is HV575~HV617, which is about 3 times of that of the based metal.