Most predatory mites feed on mites of Acaridae, Glycyphagidae and stored-grain insects. Predatory mites such as C. eruditus and C. malaccensis have been carried out a lot of experiments as natural enemy insects because of preferring hunting T. putrescentiae, A. ovatus, egg and larvae of T. confusum and T. castaneum, as well as other stored-grain pests, as natural enemies applied in the biological control technology. In recent years, since grain storage technology has been improved continuously in China and grain storage environment also has been greatly improved, major species of stored-grain pests in the grain mass have also changed a lot. In order to explore the species of predatory mites in the grain surface layer in the grain storage region with medium and high temperature, corrugated board has been used to trap the species of predatory mites in 20 grain depots in medium and high temperature grain storage ecotope. Results indicated that four kinds of predatory mites, B.tarsalis, B. keegani, C. eruditus, C. malaccensis , were found in the grain surface layer.