Abstract: Objective: To observe the accuracy of optical (PLT-O) method and electric impedance (PLT-I) method in counting the platelet by the XE-2100 automatic hematology analyzer. Methods: The platelet samples were collected from the high-value group (40 cases)(PLT > 300×10⁹/L),median-value group (40 cases)(80×10⁹/L < PLT ≤ 300×10⁹/L) and low-value group (40 cases)(PLT ≤ 80×10⁹/L). The platelet counting was conducted using PLT-O method and PLT-I method with the XE-2100 automatic hematology analyzer,and the results were compared with those by manual method. Results: The results obtained by PLT-O and PLT-I methods were consistent with those by manual method in the median-value group and the high-value platelet group (P > 0.05). However,of those lowvalue groups,the results of PLT-O are more consistent with the results of manual method than the one of PLT-I. Conclusions: The counting results by PLT-O and PLT-I methods using the XE-2100 hematology analyzer are consistent in the median-value and the highvalue platelet groups,but results by PLT-O have more important reference value in the re-examination to low-value platelet group.