Abstract: 201 stainless steel was plated with TiN and CrN coatings by arc ion plating. Electrochemical corrosion was tested in 3.5% NaCl solution, 1 mol·L-1 NaOH solution and 1 mol·L-1 H2SO4 solution. The results show that 1.2 μm dense TiN coatings and 3μm dense CrN coatings were respectively formed by arc ion plating on the surface of the 201 stainless steel. In 3.5% NaCl solution, the corrosion resistance of TiN coatings and CrN coatings are equitement to that of 201 stainless steel. In 1 mol·L-1 NaOH solution, the corrosion resistance of the TiN coatings was twice of 201 stainless steel. The corrosion resistance of the CrN coatings was about 24 times of 201 stainless steel and 12 times of TiN coatings. In 1 mol·L-1 H2SO4 solution, the corrosion resistance of TiN coatings and CrN coatings strengthen 20 times and 26 times of 201 stainless steel, respectively.