Abstract: Objective　To study the performance of creatinine testing system in China.   Methods　A total of 5 differentconcentrations of quolity control materials were distributed to 1 402 laboratoriesfor the creatinine external quality assessment（EQA），and the internal quality control（IQC） informationfor creatinine was collected in May 2011. Data were classified into differentgroups，according to 2 testing methods（Jaffe and enzymatic methods） and 11 testing systems. The results of EQA were calculated，and withoutthe outliers，the mean value（），standard deviation（s） and coefficientof variation（CV） were calculated. According to the 1/3 total allowable errors（TEa） and the quality standards based on biological variations，the system imprecision was determined. The means of difference from the EQA were used to evaluate bias for each laboratory，the accumulation CV was performed for the evaluation of imprecision，and then the sigma metric（σ） was calculated. Results　In EQA results，the CV range for Jaffe method was 1.03%-18.23% and for enzymatic method was 1.50%-8.08%. The lowest variation in Jaffe method group was in Beckman UniCel system，and the range of CV was 3.13%-4.90%. The lowest variation in enzymatic method group was in HITACHI（Roche）system，and the range of CV was 1.50%-3.00%. In the IQC results，above 80% and above 70% laboratories can pass the 1/3 TEa and the minimum performance based on biological variations，respectively，and the σ of 43% and 23% laboratories in enzymatic and Jaffe method groups can be >6. Conclusions　Between different laboratories，the variations of enzymatic method are better than those of the Jaffe method for creatinine testing system. Most testing system imprecision performance could match the minimum performance based on biological variations，and the σ of enzymatic method is better than that of Jaffe method. Performance of creatinine testing system needs to be improved in China.

Key words: Creatinine, Testing system, External quality assessment, Internal quality control, Performance