ObjectivesTo systematically review the efficacy and safety of enteral nutrition (EN) for severe acute pancreatitis (SAP) patients within 48 hours after admission.MethodsPubMed, EMbase, The Cochrane Library, CBM, CNKI and WanFang Data databases were electronically searched to collect randomized controlled trials (RCTs) on early EN (starting within 48 hours after admission) in SAP from inception to October, 2018. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies, then, meta-analysis was performed by using Stata 12.0 software.ResultsA total of 9 RCTs involving 1 074 patients were included. The results of meta-analysis showed that: compared to patients with EN after 48 hours or parental nutrition, the patients given EN within 48 hours after admission had lower mortality (RR=0.53, 95%CI 0.29 to 0.96, P=0.036) and morbidity of multiple organ dysfunction syndrome (MODS) (RR=0.58, 95%CI 0.44 to 0.77, P<0.001). However, no significant differences were found in systemic inflammatory response syndrome (SIRS) (RR=1.00, 95%CI 0.86 to 1.16, P=1.00).Conclusions The current evidence shows that EN within 48 hours after admission can reduce the mortality and morbidity of MODS in SAP patients. Due to limited quality and quantity of the included studies, more high-quality studies are needed to verify above conclusions.