Objective：To assess the clinical significance of plasma neuropeptides in patients with viral hepatitis. Methods: Levels of plasma leucinenkephalin (LENK) and neuropeptide Y (NPY) were detected with radioimmunoassay in 67 patients with hepatitis and 10 healthy controls. Results: The level of LENK in patients was significantly higher than that in controls (P<0.05). In patients with hepatitis, the level of LENK was higher in chronic hepatic failure and chronic hepatitis (severe) than that in the rest (P<0.01). The concentration of LENK was positively correlative with serum total bilirubin (TBIL) (r=0.43, P<0.01), but negatively correlative with serum albumin (ALB) (r=-0.25, P<0.05) and prothrombin time activity (PA) (r=-0.55, P<0.01). The levels of NPY in chronic hepatic failure and chronic hepatitis (severe and medium) were significantly lower than that in other viral hepatitis groups and healthy controls (P<0.01). The concentration of plasma NPY in chronic hepatitis was negatively correlated with TBIL (r=-0.34, P<0.01), but postively correlated with ALB and PA (each r=0.38, P<0.01). Conclusion: Plasma LENK and NPY levels may be used as an associated marker for judging liver function. They may contribute to the pathogenesis of viral hepatitis and some of its symptoms.