Objective: To compare the efficacy of enteral nutrition (EN) supports at different timings in treatment of severe acute pancreatitis (SAP). Methods: Sixty-four SAP patients were selected and randomly designated to observational group and control group, with 32 cases in each group. On the base of the comprehensive therapy, patients in observational group received EN support within 24 h of admission, while those in control group underwent EN support later than 48 h after admission. The serum levels of C reactive protein (CRP), total protein (TP) and albumin (ALB), time for recovery of the blood and urinary amylase levels, APACHE II scores and length of hospital stay between the two groups were compared at 2 weeks after treatment. Results: The general data were comparable between the two groups before treatment. At 2 weeks after treatment, the CRP level was significantly decreased, while the TP and ALB levels were significantly increased in observational group compared with control group, and the time for recovery of the blood and urinary amylase levels and length of hospital stay were significantly shortened versus control group; the APACHE II scores in both groups were significantly decreased compared with their pretreatment values, but the decreasing degree in observational group was significantly greater than that in control group. All the above differences had statistical significance (all P<0.05). Conclusion: For SAP patients, early EN support is beneficial for maintaining intestinal mucosal barrier function and improving nutritional status, and thereby accelerating recovery.