Objective To evaluate the performance of HORIBA ABX Yumizen H550 automatic blood cell analyzer. Methods According to the national health industry standard Quality Requirements for Analysis of Routine Items in Clinical Hematology Examination (WS/T 406-2012), the automatic blood cell analyzer was evaluated for background counting, carrying contamination, in-batch precision, linearity, accuracy, comparability of results in different suction modes, and comparability of results in the laboratory (the reference instrument was Sysmex XS800i automatic blood cell analyzer). Results The detection values of background count of all items of the automatic blood cell analyzer were met the requirements of industry standards and manufacturer’s instrument manuals, and the carryovers of white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin (HGB) and blood platelet (PLT) count of that were all passed. The results of within-run precision and inter-day precision were less than the requirements of the specifications of instrument and were far less than the requirements of standard WS/T 406-2012. Within the linearity range, the slopes of the linear regression equation were within the range of$1 \pm {0.05}$. The correlations coefficient(r)of these equations were larger than 0.975 . The pass rate that the results compared with that of Sysmex XS800i were larger than 80%. The compared results of intra clinical laboratory indicated the trueness of instrument, the outcome bias between different suction patterns. Conclusion Yumizen H550 automatic blood cell analyzer has favorable performance, accurate and reliable results. It’s an ideal automatic blood cell analyzer.