Effect of topical application with 10, 20 and 30 ${mu}g$/ml testosterone propionate and estradiol -17${eta}$ on the fourth and fifth instar bivoltine NB18 silkworm larvae Bombyx mori, on the glycogen and protein contents of the Fat body and trehalose and protein contents of the haemolymph has been studied. Glycogen content of the fat body was significantly decreased in both testosterone propionate and estradiol -17${eta}$ treatment groups except in the group treated with 30 ${mu}g$ testosterone propionate where the increase was not significant when compared with those of carrier controls. The increase/decrease in haemolymph trehalose content did not show any significant difference in all the treated groups. Protein content of the fat body significantly increased in 10 and 20 mg testosterone propionate and estradiol -l7${eta}$ treated groups but in 30 mg treated groups the increase was not significant when compared with those of carrier controls. There was no significant change in the haemolymph protein content in all the testosterone propionate and estradiol -17${eta}$ treated groups except in group treated with 10 ${mu}g$ estradiol -17${eta}$ where it showed a significant decrease when compared with that of carrier control.