A nitride layer was first formed on H13 steel samples by plasma nitriding and then a CrTiAlN coating was prepared on the surface of nitrided and non-nitrided H13 steels using closed field unbalanced magnetron sputter ion plating. The adhesion strength, the microstructure and phase structure of the film were compared between nitrided and non-nitrided H13.The results show that the substrate hardness increases after plasma nitridation and exhibits a gradient hardness transition. The complex treatment of plasma nitridation and CrTiAlN coatings could increase the adhesion strength significantly.