Abstract: Objective　To verify the main analysis performance of the UF-500i automatic urinary sediment analyzer，Sysmex，Japan.   Methods　White blood cell（WBC），red blood cell（RBC），endothelial cell（EC） and bacterium（BACT） were selected to verify the performance of the equipment. The precision was evaluated by coefficient of variation. Carryover circumstance was evaluated by carryover rates. Linear range was evaluated by regression equation，and the comparison of different equipments was evaluated by relative deviation. Results　The within-run and between-run precisions of WBC and RBC were <10%. The within-run and between-run precisions of EC and BACT were <30% and <20%，respectively. All the within-run and between-run precisions of selected testing items were within an acceptable range. The carryover rates of BACT were ＞0.05% without the requirements. All the other carryover rates of selected testing items were <0.1% within the requirements. The linear verification results got the regression equation of the theoretical and measured values after certain dilution，in which b value was within the range of 0.97-1.03（r＞0.975）. The relative deviation in different equipments was <1/2 total errors（TEa） provided by equipment production. Conclusions　The precision，carryover rates，the comparison results in different equipments and the linearity of the selected testing items of the UF-500i automatic urinary sediment analyzer meet the requirements of the laboratories in clinical diagnosis and have the clinical application significance.

Key words: Performance verification, Result comparison, Automatic urinary sediment analyzer