Abstract： Objective The purpose of the study was to evaluate the applications and value of hemoperfusion (HP) in the treatment of acute severe organophosphorus pesticide poisoning. Method Patients who had been di-agnosed with acute severe organophosphorus pesticide poisoning were selected for the study between January and October 2008. The patients were randomly divided into three groups: A group (HA230-type hemoperfutor), B group (HA330-type hemoperfutor), and C group (control group, without HP treatment). Patients in the three groups underwent the same conventional treatments except for the HP. The curative effect, cholinesterase (CHE) activities and the levels of TNF-α, IL-1β,IL-6, and IL-8 in serum were statisticaUy analyzed. Results The cure rate of the A and B groups was significantly higher than the C group (P≤0.05). The cumulative dosage of at-ropine and average hospitalization days in the C group were significantly higher than the patients in the A and B groups (P <0.01). As well, the CHE activities were obviously up-regulated after the HP h-eatment in A and B groups (P < 0.01). At 24 hours after HP treatment, the level of CHE activities in the B group was much higher than the level in the A group (P≤0.05). Levels of TNF-α, IL-1β, IL-6, and IL-8 were down-regulated after the HP treatment in the A and B groups (P < 0.01). An internal comparison revealed that the levels of TNF-α, IL-1β, IL-6 and IL-8 were lower in the B group than the A group (P <0.01). Conclusions HP can be used for treating acute severe organophosphorus pesticide poisoning, likely functioning by absorbing poisons from the blood and acting to reduco inflammatory cytokines.