Abstract: Objective:To compare the differences of results between automatic ELISA system (hereinafter referred to as automatic method) and manual method (In add liquid process is divided into direct adding reagent and the trace pipette in two ways ). Method:Using the same batch number HBsAg ELISA kit,HBsAg of 80 specimens were separately detected with manual and automatic method,and the consistency of the results of two methods was compared.One positive quality control serum was repeated measurements of 20 holes as repeatability tests by two methods,and their differences were compared.In accordance with the known concentration of positive quality control serum,the linear of automatic and manual methods were detected by 1∶2,1∶4,1∶8,1∶16,1∶32,1∶64,1∶128 dilution,and their differences were compared.The correlation coefficient,linear regression equations and expected deviation between the two methods were calculated.Result:The positive detection rate of these two methods was good consistency and there was a significant difference in determination results and precision (P<0.01).Automatic ELISA system and manual method had good correlation.The determination results were comparable in this laboratory.There were some differences and a certain expected deviation between two methods in the determination results.Conclusion:The results of automatic method would have high stability,precision and accuracy.When the automatic ELISA system occurred failure,manual operation could be served as emergency and replacement of automatic method for testing,but it should be avoided using adding reagents way.When the test results were in critical value or in the "gray area" that hard to determine by manual operation,expectation bias must be considered between the two methods to ensure the result accuracy and stability.