Abstract: 【Objective】 To provide a scientific basis for the rational use of pesticides and the cooperative biological control of Aphis gossypii by studying the effects on predation response of Coccinella undecimpunctata feeding on A. gossypii treated with sublethal doses of flonicamid. 【Methods】 According to the results of toxicity determination of LC₂₅ and LC₅₀ of flonicamid on A. gossypii, the influence of predation response of C. undecimpunctata feeding on A. gossypii treated with sublethal doses by the leaf soaking method were determined. 【Results】 The results showed that A. gossypii treated with flonicamid of different concentrations had certain influence on the predation function response and search effect of C. undecimpunctata, and with the increase of the concentration of the insecticides, the effect on the predation ability was greater. Especially after feeding A. gossypii treated with flonicamid LC₅₀, the daily maximum consumption and searching ability of C. undecimpunctata were significantly lower than that of CK, C. undecimpunctata‘s 1, 2, 3, 4 instars and adult instantaneous attack rate fell by 0.38%, 7.18%, 2.19%, 16.83% and 1.41%, the handling times required for a head of A. gossypii were extended the 0.002,4 d, 0.001,6 d, 0.000,6 d, 0.000,5 d and 0.000,1 d. The daily maximum consumption decreased by 0.72, 2.52, 7.76, 7.01 and 1.17 heads/dish, respectively. 【Conclusion】 The instantaneous attack rates of C. undecimpunctata of 1-4 instar larva and adult fed on A. gossypii treated with sublethal doses of flonicamid were reduced, the handling time was prolonged to certain degree, and the daily maximum predation amount decreased. Among them, A. gossypii treated with flonicamid LC₅₀ had the most obvious effect on the individual state of C. undecimpunctata.