Abstract: Objective The blood examination data of workers exposed to benzene and analogues were analyzed to understand the adverse effect of benzene exposure on hemocytometry. Methods The data of 2 620 exposed workers (male 1 142, female 1 186) and 2 511 control workers (male 1 437, female 1 074) were compared. Results Compared with reference group without any exposure history to benzene and analogues, the exposed workers had a lower level of leukocytes counting, particularly neutrophilic leukocytes, erythrocyte counting,hemoglobin and blood platelet counting. The number of abnormal workers was significant higher than that in the reference group. Conclusion The occupational exposure to benzene and analogues may have adverse effect on hemocytometry under current exposure level and it should be given more attention to.