Since high degree of specificity of glucose oxidase for beta-glucose had been demonstrated, the use of the enzyme, glucose oxidase and peroxidase coupled with a chromogenic oxygen acceptor such as O-dianisidine for the colorimetric determination of glucose in body fluid was proposed from several investigators. In this report the glucose level was determined in the non-and deproteinized serum and blood by means of glucose oxidase method of the Sigma Company, also the recovery rate was examined by addition of the standard glucose compatible to 50 to 100mg% with following results : 1. It was found that this method was available in the determination of blood sugar without deproteinization in nonhemolytic serum. 2. When the known amounts of glucose solution were added to the serum and blood, the recoveries were ranged from 90 to 110%.