To study the erosion wear resistance of WC-12Co composite coatings. in this paper,WC-12Co composite coatings was prepared on Q235 steel substrate by atmospheric plasma spraying (APS) method. The microstructure, phase composition and erosion wear be-havior of the obtained coatings were studied by using a variety of analytical techniques, such as XRD, SEM, EDS and self-made dry sand erosion wear tester. The mechanical properties of the coating were characterized by the Vivtorinox microhardness tester. showed that the coatings was mainly composed of WC, and a small amount of W2C, Co3W3C and Co6W6C phase. The coatings was about 300 ?m thick,the bonding coatings was about 50 ?m thick, and the cross-sectional microhardness was 1169HV0.05 at a load of 0.5 N. The maximum mass loss of the coating is 0.4788 mg/g at 60 degrees, and the minimum mass loss of the coating is about 0.3696 mg/g at 30 degrees. the wear loss firstly increase then decrease with the growth of the erosion angle, and amounted to the maximum value when the erosion angle was 60°. The coatings mainly subjected to plastic wear at the small angle (30°) while it subjected to brittle one at the large angle (90°).