Abstract: Iron base amorphous alloy coatings and iron base amorphous and nanocrystalline alloy coatings were deposited on 0Cr13Ni5Mo stainless steel by high velocity oxy-fuel (HVOF) thermal spraying and air plasma spraying (APS). Wear resistance and wear mechanism were studied. Experiment results show that wear mechanism of air plasma sprayed coatings was mostly particle wear. However, wear mechanism of high velocity oxy-fuel thermal sprayed coatings was mainly fatigue wear. Iron base amorphous and nanocrystalline alloy coatings deposited by air plasma spraying (APS) was more wear resistant than iron base amorphous alloy coatings deposited by high velocity oxy-fuel (HVOF) thermal spraying. This was attributed to higher hardness and nanocrystalline particle for iron base amorphous and nanocrystalline alloy coatings deposited by air plasma spraying (APS) which enhanced wear resistance of the coatings.