Abstract: Objective To study the effects of calibra tors in unifying the results of di fferent analyzer/reagent systems. Methods The ac tivities of ALT, AST, CK，GGT, LD in 150 and ALP in 100 fresh sera were measured by using four an alyzer/reagent systems , and the mean values of different systems were compared between, before and afte r calibration with calibrators. ResultsThe d ifferences among the results of fou r systems were observed before calibration. The coefficient s of variation(CVs) are all more than or cqual to 7.0%,more r emarkably these of ALP and GGT are 27.0%and 17.4%respectively. After calibr ation, the differences a re decreased clearly and the CVs are all lower than 5%except that ALP and GGT are 6.6%and 5.1%respectively. ConclusionEnzym e calibrators could be useful in standardizing the results of different analyzer/reagent systems.