Objective: To investigate the ranges of reference values of GGT in urine by determining active GGT in urine of 1 118 healthy people. Methods: The active GGt in urine was measured by a continuous monitoring with γ glutamyle 3 carboxy 4 nirroanilide (GCNA) as substrate, which was recommended by International Federation of Chemistry Committee (IFFC). The results were processed and analysed by Statistical Package for Social Science (SPSS). Results: The reference value of GGT of general in urine was 0 to 61.42 u/L, that of men and women in urine were 0 to 62.08 u/L and 0 to 60.87 u/L respectively. Conclusion: The method that active GGT was determined with GCNA as substrate by a continuous monitoring was simple, convenient, high speeded, and practicable, and could be used in the clinical routine test. There was almost no difference between men and women on the GGT value in urine.