Abstract: Objective To investigate the change of gut-barrier function of mice in acute organophosphorus poisoning and the protection effect of benthiactzine. Method A total of 65 Kunming mice, female and male both half, were randomly assigned to five groups: normal group, DDVP poisoning(model) group, and benthiactzine 2, sured by spectrophotometric assay at 3 hours after DDVP poisoning. The variance analysis was used to deal the quantitative data. Results The DAO activity in model group significantly increased compared with normal group (P < 0.01). Whereas, the DAO activity in all pretreatment groups were significantly decreased compared with concentration of D-lactate in model group was significantly increased compared with normal group (P < 0.01). However, the concentration of D-lactate in pretreatment groups was significantly decreased compared with model group(all P < 0.01). The concentration of D-lactate could be decreased dose-dependently by the administration of benthiactzine. Conclusions The diamine oxidase activity and concentration of D-lactate were significantly in-creased in the DDVP poisoning mice, which means the gnt-barrier function was severely damaged. And the admin-istration of benthiactzine could alleviate the injury to the gut-barrier function.