Diagnostic membranes which were made of polyphosphazenes were prepared for the measurements of bloodglucose concentration. The effects of possible interferents in human blood on the glucose concentration measurements wereexamined. Above those interferents, ascorbic acid (AA) showed 3~9% higher K/S values compared to the standard plasmasolution, tolbutamide (TA) showed 11~13% lower K/S values than those of plasma, triglycerides and bovine serum albumin(BSA) showed 20~25% lower K/S values than those of plasma. However, most of the interferents except above materialsdid not show any serious effects on the blood glucose measurements.