Uricase-immobilized silk fibroin membrane was characterized by means of electrochemistry method. When uricase was immobilized in silk fibroin membrane, the immobilized uricase was improved largely at its stability to heat and pH, and it can be stored for long time. Based on this uricase membrane and oxygen electrode, an amperometric sensor has been developed for measurement of uric acid in flow injection analysis. The biosensor has a good reproducibility for repeatedly monitoring biosamples for 100 times respectively and is capable of detecting over 60 serum samples per hour.