Soybean (Glycine max L.) is one of the miracles Golden Bean 'of the 20th century. Soybean possess a very high nutritional value, on an average it contains 20 percent oil, 40 percent protein, vit A, B, 100, 500, E and K along with 0.69 per cent phosphorus, 0.112 per cent, iron and 0.024 per cent, of calcium. Edible soy proteins are one of the world's least expensive and high quality protein source. This crop is attacked by 88 insect pest species. Among them, the leaf defoliata's viz., Tobacco leaf eating caterpillar (Spodoptera litura Fab) and green semilooper (Chrysodeixis acuta) ) are the noxious pests that damage the soybean crop extensively by skeletonizing the leaves and thus reducing the photosynthetic capacity of the plant.The Present study entitles "Validation of different insecticides against defoliators on Soybean" were help in selection of most effective chemical insecticide against major defoliator pests of Soybean.