The predatory flower bug Orius similis Zheng (Hemiptera: Anthocoridae) is an important natural enemy of agricultural pests. In this study, O. similis was reared on eggs of the rice moth, Corcyra cephalonica Stainton, and the two-spotted spider mite, Tetranychus urticae Koch. Through analysis of life tables and the functional response of the predator, the effect of two prey species on the population growth of O. similis was determined in the laboratory. The stage-specific life table parameters of O. similis when feeding on eggs of C. cephalonica were: average generation time (T) of 24.3500 d; sex ratio (P_♀) of 52.50%; average fecundity (F P_F) of 37.2857; index of population trend (I) of 9.2118; finite rate of increase (λ) of 1.0955 and intrinsic rate of increase (r_m) of 0.0912. In contrast, when feeding on T. urticae, O. similis completed its development and mated, but females did not produce any eggs. Survival rate of O. similis first instar nymphs when feeding on T. urticae was 81.19%, which was much lower than other instars (all greater than 89.5%). The average time from egg hatching to death of the adult was 19.3716 d. Comparing the effects of the consumption of these two prey species on O. similis stage duration, Adult survival of O. similis was 83.33% when feeding on eggs of C.cephalonica and 59.68% when feeding on T. urticae. average development time of O. similis nymphs consuming eggs of C. cephalonica (11.0633 d) was shorter than those consuming T. urticae (13.8950 d). The average adult longevity of O. similis consuming eggs of C. cephalonica (9.9750 d) was significantly longer than those consuming T. urticae (5.7297 d). These results show that eggs of C. cephalonica meet the nutritional requirements of O. similis, and that this prey species can be used to rear O. similis in the laboratory. O. similis could not successfully reproduce when consuming only T. urticae and so this species cannot be used to rear O. similis. Our results have implications for the feasibility of mass rearing O. similis in an indoor environment. The functional response of O. similis adults that were feeding on T. urticae adults could be explained as a Holling Type II response, with a handling time (Th) of 0.0108 min, rate of instantaneous attack (a) of 0.8253 and maximum daily predation (Na_max) of 92.59 d^-1. Based on these results and those from other studies, it is suggested that T. urticae could be controlled by O. similis with an appropriate method.