The nano and micro WC-17Co coatings were fabricated on the 0Cr13Ni5Mo stainless steel by supersonic plasma spraying method. The porosity, adhesive strength, hardness and wear resistance of both coatings were compared. The results indicate that the porosity and adhesive strength of nano-coating (i.e., 0.56% and over 69.2 MPa) are higher than those of micro-coating. The hardness of nano-coating and micro-coating are 3.9 and 3.8 times more than that of matrix, respectively. The hardness of both coating will gradually increase from its top to bottom. The wear mechanisms of matrix were adhesive wear, abrasive wear and delamination, while the coatings only suffered adhesive wear. The lower porosity, higer hardness and stonger compressive resistance of nano-coating result in its excellent wear resistance.