Abstract: Composite coatings with micro/nano scale TiN reinforcing phases were successfully fabricated by pre-nitriding+pulse laser cladding treatments on TC4 substrate surface. A comparative research on microstructures and mechanical properties were carried out between the pre-nitriding+cladding(PNC) composite coatings and the conventional laser gas nitriding(LGN) samples. The results showed that the PNC composite coatings were composed of TiN and ' martensite. With the contents of N in powder mixtures augmenting, the hardness increased gradually. Comparative analysis indicated that, the hardness properties of the PNC composite coatings were equivalent with that of LGN samples. In addition, the PNC composite coatings displayed better homogeneity of hardness along depth direction than that of the LGN samples. Based on data fitting, an empirical formula was tentatively developed to estimate the hardness of PNC coatings.