Abstract: Objective: the accuracy ofblood cell analyzer on the results of the new purchase.Method: to ACT diff2 as the control instrument (because of their participating in the annual Anhui province EQA results were excellent), the analysis of Sysmex KX-21 type test instrument to buy a new result accuracy. According to EP9A-2 files steps, with fresh blood 40 (including normal and abnormal results) in the two instruments were measured, 2 h all the samples. 8 blood samples every day, each instrument measured 2 times, were measured by 1, 2, 3, 4, 5, 6, 7, 8, 8, 7, 6, 5, 4, 3, 2, 1 sequence, measuring a total of 5 d. Records of the results of detection of platelet leukocyte, erythrocyte, hemoglobin, hematocrit, 5 parameters.Results: 5 the inspection results of the parameters of test instrument and control instrument good correlation (r 0.975), test instrument each project at medical decision level relative deviation is less than the clinical laboratory modified regulations allowed error of 1/2 standard.Conclusion:as a new test results between test results for instrument and control instrument are comparable, the detection result is accurate and reliable, and can be used for clinical detection of blood cells.