The work aims to obtain optimized composition of high quality plasma cladded Fe-based coatings. Fe-based coatings were synthesized in situ on Q235 steel in reactive plasma cladding method with Fe901 alloy, Ti and B4C powders as raw materials. The effects of (Ti+B4C)/Fe901 mass ratio (15/85, 25/75 and 35/65) on formation of reinforcement phases in the coatings, interfacial bonding, microstructure and microhardness of the coatings were investigated. The Fe-based coatings are metallurgically bonded to the substrate. The quality of interface joint deteriorates when (Ti+B4C)/Fe901 mass ratio is high. The coating mainly consists of (Fe, Cr) solid solution, TiB2, TiC, Ti8C5, Fe3C and FeB phases provided with (Ti+B4C)/Fe901 mass ratio of 15/85. Increasing the (Ti+B4C)/Fe901 mass ratio might not result in formation of a new phase, but it can inhibit FeB precipitation. TiC in the coatings takes shape by multi-steps reaction. Microhardness of the coatings generally increases as the (Ti+B4C)/Fe901 ratio increases, and is on the rise on the whole. When (Ti+B4C)/Fe901 ratio is not more than 25/75, microstructure of the coatings is relatively uniform and the microhardness varies steadily along the depth direction. However, the microstructure and microhardness of the coating presents gradient distribution as (Ti+B4C)/Fe901 ratio further increased. Microhardness difference between the upper and lower coating can be up to 630HV0.1. The plasma cladded Fe-based coatings with gradient or uniform microstructure and microhardness can be obtained by adjusting reactant content of the main reinforcement phases, so as to meet different practical application requirements.