The influence of proceeding treatment technology on properties of Ni-HAP composite coating was investigated. From the results, the degree of combination of the matrix being treated by electropolishing with the composite coating was denser and firmer than that of the matrix being treated by mechemical polishing with the composite coating. As a result, a new-applied noncorrosive steel-based Ni-HAP composite biomaterial was produced. Moreover, a tentative study about the technology and mechanism of getting high-MAP contents coating was done.