Abstract: Objective　To evaluate the performance of COBIO automatic urine system（combi XL analyzer and COBIO xs automatic urine sediment analyzer）. Methods　The repeatability，linearity，accuracy and sensitivity were determined by COBIO automatic urine system. Results　The within-run coefficients of variation（CV%） of white blood cell in high，middle and low-value samples were 4.5，6.0 and 10 respectively. They were 2.4，5.0 and 13.8 for red blood cell，and 4.8，7.0 and 13.5 for epithelial cell. The correlation coefficient of red blood cell was 0.999 with 5-1210/μL. The correlation coefficient of white blood cell was 0.998 with 4-498/μL. The accuracies of red blood cell，white blood cell，epithelial cell，cast cell，calcium oxalate，uric acid crystallization and Candida were 99%，98%，93%，58%，93%，95% and 90%，recpectively. Conclusions　COBIO automatic urine system has the advantages of automation，high testing speed，accuracy and low cost，and it has a good significance in clinical application.

Key words: Automatic urine analyzer, Assembling line, Urine sediment analysis, Evaluation