The effect of chemical insecticides on the structure and diversity of arthropods in various tea gardens were investigated. Results showed that the effect of chemical insecticides on the arthropods in tea gardens reflected in the structure and the constitution of species, the diversity index and the distributive evenness of species. The index of population density of dominant insect pest was increased greatly in those tea gardens with higher chemical insecticide expense, especially for tea leaf hopper (Empoasca vitis Gotho). The regulatory effect of natural enemies on major insect pest was increased in those tea gardens with lower expenses of insecticides. Besides, the diversity index and the evenness index were increased at the same time.