ObjectiveTo evaluate the complete blood count performance quality of Sysmex-XN automatic hematology analyzer. MethodsWe investigated the precision rate, residual contamination rate, analytic linearity range, and background counting of Sysmex-XN-B3 analyzer. ResultsThe inner and inter-group precision test showed that the inaccuracy of the analyzer was lower than the allowable standard of 1/4 (CLIA'88). The highest level of residual contamination rate was 0.12%, lower than the standard of manufacturer (≤1%). Linearity evaluation showed that the white blood cell count analytic linear range was from 0.51×109/L to 393.40×109/L, the red blood cell count analytic linear range was from 0.51×1012/L to 8.15×1012/L, the hemoglobin analytic linear range from 15.0 g/L to 244.5 g/L, and the platelet count analytic linear range was from 3.0×109/L to 2 072.5×109/L. Background counting was also lower than the standard of manufacturer. Comparison between the two different series of analyzers showed that the inaccuracy rate of Sysmex-XN-B3 was not only lower than the standard of National Center for Clinical Laboratories, but also lower than the standard of 1/2 (CLIA'88). ConclusionSysmex-XN automatic hematology analyzer has a high performance in capability evaluation. It is an excellent tool for routine hematologic blood examination.