Objective: To investigate the effect of Shen-Fu (SF) injection on gastrointestinal tract injury and its potential mechanism. Methods: Thirty-eight patients undergoing elective open heart surgery were assigned to Group C (control group, n=18) and Group SF (n=20) randomly. In Group SF, the patients received intravenous injection of SF (0.5 ml/kg) at the beginning of the surgery followed by a continuous infusion of 100 ml SF (1.0 ml/kg) solution diluted by saline at a rate of 0.004 ml*Kg-1*min-1with a Grasby pump. The control group was injected with normal saline in the same volume. Gastric intramucosal pH (pHi), activity of blood diamine oxidase (DAO), and concentrations of blood LPS and IL-6 were measured before CPB (S0) and 1 h (S1) and 2 h (S2) after aortic declamping, respectively.Results: In Group C, pHi value was significantly lower at S1 and S2 than at S0 ( mean P<0.01) and blood DAO and concentrations of LPS and IL-6 were significantly higher at S1 and S2 than at S0 ( meanP<0.01). In Group SF, pHi was obviously lower at S1 and S2 than at S0 (P<0.05) but LPS and IL-6 levels and DAO were higher at S0 (mean P<0.05). Blood DAO and LPS level demonstrated significant negative correlations with pHi (mean P<0.01) while LPS concentration showed a positive correlation with blood DAO (P<0.01) and IL-6 concentration(P<0.05). At S1 and S2 after aortic declamping, the levels of pHi were higher in Group SF than in Group C (mean P<0.01 ) but DAO and LPS and IL-6 levels were significantly lower in Group SF than in Group C ( P<0.01).Conclusions: SF has a protective effect on gastrointestinal tract and can reduce inflammatory actions.