Objective To investigate the different biochemical testing system inter laboratory comparability of results,provide reference for promoting inter laboratory test results of the recognition.Methods Five patients with laboratory detection of fresh mixed serum,20 consecutive determination of 10 biochemical items,precision analysis.According to America clinical and Laboratory Standards Institute (CLSI)Document EP9-A2,the Panzhihua Iron and Steel Group General Hospital detec-tion system as the reference system,the remaining four hospital detection system as the detection system,with a fresh mixed serum,determination of five biochemical items (Urea,Cr),(AST,ALT),(TP,ALB),(TG,TC)and (HDL-C,LDL-C),the determination results were compared and analyzed,calculated reference system and the correlation coefficient,linear regres-sion equation between the system and the various medical decision level relative deviation (SE%),and to America Clinical Laboratory Improvement Amendment ability test (CLIA’88)allowed total error of 1/2 as the standard,to the assessment system and the reference system between the comparability and clinical acceptability.Results In Urea,Cr determination for example,CV of five laboratories on Urea and Cr two project was less than CLIA’88 allowed total error of 1/3,the precision could meet the clinical requirements.The detection results significantly correlated (r2 >0.975).The evaluation of clinical ac-ceptability,in Urea low at medical decision level,there were two laboratory determination results that could not be accepted for clinical.In Urea high at medical decision level,there was a laboratory measurement result that could not be accepted for clinical.In the low Cr at medical decision level,there were two laboratory determination results that could not be accepted for clinical.The rest of the system Urea,Cr projects in various medical decision level compared with the system,the SE% was less than CLIA’88 allowed total error of 1/2,for clinical acceptable.Conclusion Laboratory determination results between different biochemical testing system had bias in different degrees,bias part of the project exceeds the allowed error range.