Glucose oxidase (GOD) and Horseradish peroxidase (HRP) were covalently coupled to alkylamine controlled pore glass by means of glutaraldehyde. About 700-800 U/g of immobilized GOD and 300-400 U/g of immobilized HRP were obtained. Some factors of affecting enzyme immobilization were discussed. The immobilized enzymes were packed into a plastic tube and used in flow-injection analysis (FIA) for glucose in serum. A good linearity range was observed for this immobilized enzyme system at 20 mg/mL to 1000 mg/dL D-glucose, the recovery was 95.4-103.5%, the within-batch imprecision was 0.8-2.2%, and the between-batch imprecision was 2.2-4.2%. More than 100 samples were measured within an hour. One enzyme column with five units of immobilized GOD and HRP, applied for 50 assays/d, has been used for more than 2 mo.