Predatory natural enemies play an important role in the natural control of pests. When pests occur, chemical pesticides are needed for effective control, but they may affect the survival of predatory natural enemies. Therefore, understanding the effects of pesticides on predatory natural enemies is needed to better coordinate the use of chemical and biological controls. Most pesticides inhibit the growth and reproduction of predatory natural enemies, but some promote them. Prey detection capacibility of most predators is reduced when exposed to pesticides. Some pesticides affect the predation behavior and predation function of predatory natural enemies. Some pesticides directly convert predation function model from Holling-Ⅱ to Holling-Ⅰ. Under pesticide stress, predatory natural enemies develop pesticide resistance, by increasing detoxification enzyme activity or decreasing target site sensitivity. The research on the effects of pesticides on predatory natural enemies has both theoretical and practical significance for the combined use of chemical and biological control in integrated pest management (IPM).