[Objective] The aim was to clear the occurring dynamics of main insect pests in cotton field in Turpan and screen insecticides.[Method] We investigated systemic regularity of outbreak of main insect pests in field and selected effective prevention medicament.[Result] By 3 years continuous investigation,the main pests in cotton field in Turpan were Aphis gossypii,Helicoverpa armigera and Bemisia tabaci.Aphis gossypii reached doublet variation tendency,reaching the top in mid-June and early in July.Helicoverpa armigera waved irregularly,and Bemis...