Performance Characteristic Comparison of two kind HBsAg ELISA kits with Different Incubation Time Shen MN, Song BB, Guo W, Pan BS Shanghai Jiaotong University School of Medicine, Department of Laboratory Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China. Objective: To compare the performance characteristic of two HBsAg ELISA kits with different incubation times (30min and 60min). Method: Two HBsAg ELISA kits from the same manufacturer, with 30 min and 60 min incubation time were used to assay the same batch of patient sera. The results were compared and the performance characteristic including precision, ability of interference resistance and results agreement between the two kits were compared. Results: The bias of precision between the two kits had no significant deviation. Intra-assay imprecision (CV) were within 10% and Inter-assay imprecision (CV) were within 15%; hemoglobin (<4.0g/L), triglyeride (<2.2mmol/L), bilirubin (<260µmol/L) could not interfere the test results; 229 samples were parallel tested by the two kits, there were 33 discrepant results of which samples tested with ECLIA were all weakly reactive. Conclusion: Precision and ability of interference resistance of the two kits had no significant different but the kit of 60 minutes incubation time had a higher sensitivity.