Objective To evaluate Sysmex XS-800i,XS-1000i and XE-2100D hematology analyzers when used to detect RBC count,hemoglobin (HGB),hematocrit (HCT),mean corpuscular volume (MCV),mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC).Methods XE-2100D hematology analyzer was calibrated after performance evaluation,and the three analyzers had the intra-day precisions measured with three levels of whole-blood quality control materials.Totally 50 whole-blood specimens were detected with the three analyzers respectively,and statistical analyses and clinically acceptable performance evaluation were carried out on RBC count and the obtained results.Results XE-2100D hematology analyzer met the clinical requirements,and the three analyzers all gained high precisions when used to measure the parameters of the whole-blood quality control materials.The correlation coefficients (r2) respectively between the three analyzers were all higher than 0.95 when used to test the 50 specimens.At all medical decision levels XS-800i and XS-1000i hematology analyzers both gained acceptable detection results except XS-800i hematology analyzer in case of 5.9×1012/L RBC count as well as 35％ or 50％ HCT.Conclusion Sysmex XS-800i,XS-1000i and XE-2100D hematology analyzers have high precisions and correlations when used to detect RBC count,HGB,HCT and MCV,and contrast test is suggested to be executed periodically to ensure the comparability of tbe result.