Ni-P-(nano)TiO2 composite coating was prepared by electroless composite plating. The effects of nano-TiO2 addition on microstructure, hardness, wear resistance, porosity and corrosion resistance of Ni-P composite coating were investigated and the mechanism was discussed. The results show that TiO2 nanoparticles are homogeneously distributed in the Ni based coatings, without apparent aggregation. The dispersion strengthening effect of the nano-TiO2 particles leads to high hardness and good wear resistance of the composite coating. The surface hardness of the crystallized composite coating can reach 10925 MPa and the wear resistance increases greatly. However, nano-TiO2 particles addition increases the porosity of the coating, decreases the corrosion resistance to NaOH and NaCl solution slightly, and the corrosion resistance to HCl becomes poor.