The incorporation of activity in plasma lipid was determined after injection of u-C^(14)-glucose to normal laying hen. The extraction of total lipid from plasma was carried out by the method of Floch et al. with some modifications. The counting of carbon-14 activity was conducted by a Beckman Liquid Scintillation System, The concentration of plasma lipid was estimated as much as 3, 070㎎ per 100㎖ of plasma taken at 5 minutes after injection of tracer amount of u-C^(14)-glucose. The specific activity per gram of plasma lipid carbon atom per injected dose per ㎏ body weight increased gradually following the time after injection until 120 minutes, whereas the glucose activity decreased logarithmically. The partial incorporation quotient cf activity in plasma lipid from that of glucose was 0.73% until 120 minutes after the injection.