Cheyletuseruditus (Schrank) is widely existed in grain depots and warehouse, which is an ideal natural enemy resources with control potentialagainst pests and mites, especially for eggs and young larvae.In order to evaluate its biological control potential to Acarussiro (Linnaeus), functional response analyses were conducted of three C. eruditusstages, protonymph, deutonymph and female adult to four Acarussiro stages, eggs, larve, nymphs and adult.The results showed that the predation function of C.eruditusprotonymphs, deutonymphs and female adult all belonged to the HollingⅡtype to four stages of Acarussiro. The predation ability of female adult was the highest, and its attacking efficiency on different stages of Acarussiro was 0.913 (egg), 1.030 (larva), 1.017 (deutonymph), 0.989 (adult) respectively. The female adult of C.eruditus preferred to the larvae, with the maximum predatory efficiency 42.436 larvae per day. In terms of the predatory capacity of C.eruditus to Acarussiro, female adult showed the highest potential in preying different stages of Acarussiro except for the eggs, then was deutonymph. C.eruditus was the mostpotential native Phytoseiid species that might be used in Acarussiro control. This study laid a foundation parameter for the control of stored grain pest and mites by C. eruditus, and provided a reference for the further application of C. eruditus to control pest insects and mites.