A survey was undertaken in different farmer’s field to study the diversity of major insect pests and their predators in brinjal ecosystem. The study revealed 6 species of herbivores and 9 species of predators in field. Among the herbivores Aphis gossypii, Amrasca biguttula biguttula, Leucinodes orbonalis and among the predators Coccinella transversalis were dominant during the study period. It was found that, species richness (R) of herbivores was highest at reproductive stage (2.073) followed by vegetative Stage (2.006) and lowest in harvesting stage (1.542).Whereas, the diversity index and evenness was more in harvesting stage (1.280 and 0.485) followed by reproductive stage (0.819 and 0.289) and lowest in vegetative Stage (0.505 and 0.197). Highest species richness of predator was found at reproductive stage (3.037) followed by vegetative Stage (2.968) and lowest at harvesting stage (2.730) while diversity index was maximum in vegetative Stage (2.442) and minimum in Harvesting stage. The predator evenness was recorded highest in harvesting stage (1.001) and lowest in reproductive stage (0.913).