Abstract: Objective:To evaluate the results of serum electrolytes by two automatic biochemistry analyzer systems:7600-020 fullautomatic biochemical analyzer(Hitachi,Japan) and VITROS 350 dry-type biochemistry analyzer(Johnson,US),and assess the bias, which to ensure the consistency of test results. Methods:According to the National Committee for clinical laboratory standards EP9-A documents,7600-020 system was as control,Vitros-350 system was as experimental instrument,measure serum electrolytes by the two instruments,record the data,check the discrete point,calculate linear equations and correlation coefficients(r),and carry on the bias estimation. Results:Correlations between the two instruments were fine enough(P<0.05) and the clinical acceptability assessments did not exceed half of the acceptable error by CLIA'88. Conclusions:The electrolyte results which determined by Hitachi 7600-020 automatic biochemical analyzer and Johnson Vitros-350 dry type biochemistry analyzer are basically consistent and have a good comparability,either of the two instruments can be selected to do electrolyte determination.