Abstract： Objective To evaluate the effect of enteral nutrition by a polymeric formula in patients with severe acute pancreatitis (SAP).Methods Fifty-eight patients with SAP were randomly divided into polymeric group (29 cases) and semi-elemental group (29 cases),and the two groups of patients were treated in accordance with the conventional SAP management protocol,nasojejunal tube was endoscopically inserted for enteral nutrition.The polymeric group received enteral nutritional suspension (TPF),and the semi-elemental group received the same quantity of VIVONEX TEN.The gastrointestinal tolerance (VAS score),incidence of diarrhea,infection,28-day mortality rate,and length of hospital stay was evaluated.Nutritional parameters were evaluated by pre-albumin,albumin,alanine aminotransferase,C reactive protein at the time of admission and one week later.Results The two groups of patients were comparable in terms of VAS score,incidence of diarrhea,infection,28-day mortality rate,and length of hospital stay (P ＞0.05).And the levels of prealbumin,albumin,alanine aminotransferase,C reactive protein after admission were not statistically significant (P ＞ 0.05).Conclusions Compared with the semi-dement formula,the price of polymeric formula is cheap,configuration is convenint,enteral nutrition is well tolerated,and it is suitable for early enteral nutrition in SAP.