Objective To explore the clinical value of early enteral nutrition in severe acute pancreatitis （SAP） by percutaneous endoscopic gastrostomy/jejunostomy （PEG/J）.Methods Treatment condition of nighty patients with SAP were retrospectively analysed.The 90 patients were collected peripheral venous blood respectively on 1，?12，?and 18 d after admission to hospital.Forty-five of them were in PEG/J group，?the others were in control group. Serum IL-6，TNF-α and endotoxin were detected by enzyme-linked immunosorbent assay （ELISA），CD4 /CD8 was determinated by indirect immunofluorescence staining method （FITC-labeled）.Results On 12 d and 18 d，the levels of serum IL-6，?TNF-α，?and endotoxin in PEG/J group were lower than those in control group （P＜0.01）.The CD4 /CD8 was significantly higher than that in control group （P＜0.01）.In control group，?2 cases complicated upper gastrointestinal haemorrhage，4 cases complicated pancreatic pseudocysts，?and 2 cases complicated double infection，?the temperature became normal after about 13.5 d.In PEG/J group，?there were not upper gastrointestinal haemorrhage and double infection，but 2 cases also complicated pancreatic pseudocysts，?the temperature became normal after about 10.5 d.Conclusion The clinical effectiveness of early enteral nutrition in SAP by PEG/J is satisfactory.