Abstract: The decarburization resistance experiments of a coating mainly composed of attapulgite for GCr15 bearing steel were conducted. The performance and mechanism of decarburization resistance of the coating at high temperatures were investigated by optical microscopy and x-ray diffraction analysis. The results indicated that the coating could reduce the depth of decarburization layer significantly. The anti-decarburization performance of the coating kept very well even with the extension of the holding time and the increase of heating temperature. The protection of the coating was obtained by the formation of a dense layer on the surface of the alloy and the oxidation of SiC inside the coating.