[Objectives]  To investigate the effects of organic manure on rice paddy arthropod communities, including predators and rice pests, and determine whether this increases the abundance of important rice pests. [Methods]  Single- season rice was planted for two consecutive years (2017-2018) in two kinds of rice paddy; one which used organic manure (RPOM) and another which used chemical fertilizer (RPCF). Soil fertility and the abundance of aquatic insects, spiders, predatory insects, functional rice pest groups, and the compensatory prey of predators in both field types were investigated，and predator-to-pest ratios for species richness and individual species abundance calculated. [Results]  Alkali-hydrolyzable N, available P, total P and total K were significantly higher in the soil of the RPOM than in the RPCF (P<0.05). Total N and organic matter in the soil of the RPOM was also much higher than in RPCF (P<0.01). The number of aquatic insects in the RPCF was significantly lower than in the RPOM. There was no significant difference in the total number of Chironomus and Collembola between the RPOM and RPCF. In 2017, 887 rice insect pests belonging to 17 species were collected in the RPOM compared to 917 rice insect pests belonging to 18 species in the RPCF; a similarity coefficient of community of 0.86. In 2018，1 226 rice pests belonging to 13 species, and 2 035 rice pests belonging to 15 species, were collected in the RPOM and RPCF, respectively. The similarity coefficient of community was 0.71 between the two paddy types. The number of individual rice insect pests was significantly higher in the RPCF than in the RPOM. In 2017, 1 316 predatory predators belonging to 41 species were collected in the RPOM compared to 989 belonging to 31 species were collected in the RPCF; a similarity coefficient of community of 0.83 and a Bray-Curtis distance of community of 0.151. In 2018, 1 537 predators belonging to 41 species were collected in the RPOM compared to 1 031 belonging to 36 species in the RPCF, with a similarity coefficient of community of 0.78 and a Bray-Curtis distance of community of 0.31. The diversity of predatory species in the RPOM was significantly higher than that in the RPCF in 2 consecutive years, a difference that was highly significant in 2018 (P<0.01). Furthermore, the number of individual insects in the RPOM was significantly higher than in the RPCF (P<0.05). The ratio of predatory species to insect pests in the RPOM and RPCF were 1.86 and 1.09 in 2017, and 1.64 and 0.64 in 2018, respectively, and was significantly higher in the RPOM than in the RPCF in 2018 (P<0.05). [Conclusion]  Organic manure markedly improves the soil fertility of paddy fields, has no significant effect on the abundance of compensatory prey, and reduces the number of insect pests, which suggests a bottom-up effect. However, the species richness, abundance of predatory species, and the ratio of predatory species to insect pests, were significantly higher in fields with organic manure, suggesting a top-down effect. These results demonstrate that the addition of organic manure enhances the ecological control effect of the natural enemies of insect pests.