Present communication deals with quantitative determination of total lipid, triglycerides, total free fatty acids, phospholipids and total cholesterol in the fat body tissue of the silkworm adapted to low and high temperatures. At the end of spinning process is characterized by a marked cellular reorganization of the different lipid fraction of the fat body irrespective of thermal acclimation. Accordingly, the per cent composition of triglycerides of the total lipid is increased accompanied by a corresponding decrease in free fatty acids, phospholipids and cholesterol.