Abstract: Objective　To compare the difference between the total errors（TE） in the determinations of serum potassium ion（K⁺） and sodium ion（Na⁺） determinations with clinical quality requirements.   Methods　The quality control results of K^＋ and Na^＋ during 9 months were analyzed statistically by Unity Real TimeTM quality control software，and the means（），standard deviations（s） and coefficients of variation（CV） were calculated. All the internal quality control results were compared with those of the same group in bias，standard deviation index（SDI），coefficientof variation ratio（CVR） and TE. The clinical questionnaires related to the allowable total error（TEa） of K^＋and Na^＋ were carried outand analyzed. The agreementof testing qualityfor K^＋ and Na^＋ was evaluated and compared with thosefrom domestic and abroad quality standards，biological variation and the clinical requirements in our hospital. Results　The averages of CV，CVR，SDI，bias and TE of K^＋and Na+ were 1.37%，0.68，0.44，1.14%，3.40% and 0.94%，0.85，0.19，0.17%，1.72%，respectively. The clinical requirementsfor average TEa of K^＋and Na^＋ were 1.63% and 1.03%，respectively. Atthe cut-off values of K^＋（5.0 mmol/L atupper limitand 3.5mmol/L atlower limit），the CV were 1.0% and 1.5%，respectively. Atthe cut-off values of Na^＋（155 mmol/L atupper limitand 135mmol/L atlower limit），the CV were both 0.9%. The testing qualityfor K^＋all reached the standards of many nations and regions，and was within the range of biological variations，and so did thosefor Na⁺ exceptbiological variations. In view of clinical requirements，both K^＋ and Na⁺ testing qualities had some differences. Conclusions　The laboratory should provide the combined uncertainty in measurementof serum K^＋ and Na^＋ while reporting the testing results. Laboratory personnels should take measures to reduce the TE and improve the quality together with clinical doctors by continuing communication. Key words：Potassium ion；Sodium ion；Total error；Quality requirement

Key words: Potassium ion, Sodium ion, Total error, Quality requirement