Bombyx mori L. is a commercial exploited variety used large scale production of silk. One of the most important characteristics of the silkworm, B.mori is its ability to switch plant protein from feeding material to silk protein. The current study revealed that the impact of feeding B.mori with plant and animal protein enriched mulberry leaves has been examined with reference to biochemical content and economic parameters of sericulture. Fortification of the mulberry leaves by nutrient supplementation can be increased the quality and productivity of silk. The feeding of mulberry leaves soaked in 3, 5 and 7 per cent plant protein (soya flour) and animal proteins (T. castaneum larvae) to B.mori larvae from the first day of third, fourth and fifth instar. Biochemical constituents such as protein, carbohydrate and lipid content of silk gland, haemolymph, fat body and muscles were noted. B.mori proteins are stored in the middle silk gland and they are discharged through the anterior duct and spinneret, at the end of the fifth instar. The highest silk gland protein (92.01 per cent) was noted in the anterior silk gland at the 5 per cent soya flour treated groups. During the feeding period of the last larval instar, all the major proteins are synthesized by the fat body and secreted in to the haemolymph for temporary accumulation. The results of present study clearly demonstrated that the protein content of haemolymph and fat body were 55.68 and 36.25 per cent significantly increase when the larvae fed with 7 and 3 per cent soya treated groups. Among the treatments 5 % animal protein showed a significant increase in shell ratio (19.44 per cent) and filament length (81.26 per cent) and 7 % plant protein showed significant increase above parameters (18.66 and 80.43 per cent) when compared to control.