<正> Plasma fibronectin was determined serially with both simpleradioimmunadiffasion and modified indirect hemoagglutination test（usinggelatin-coated sheep RBC）in 30 patients with severe viral hepatitis（SVH）

100normal subjects and 30 cases of chronic active hepatitis（CAH）were also studiedto serve as controls.Liver function test

serum complement 3 and immunoglobulinwere determined simultaneously.Endotoxin was assayed with limulus lysate testin 21 cases of SVH and 14 cases of CAH.The normal value of plasma fibronectin was 284.31±45.56μg/ml and 1:30.64（geometrical mean）.Plasma fibronectin level decreased significantly in SVHpatients.Obvious correlations were found between the levels of plasma fibronectinand the valuers of total serum bilirubin

prothrombin time

complement 3

immunoglobulin M

and blood platelet count.Low plasma fibronectin levels wereremarkably associated with the occurrence of endotoxemia.It is concluded that serial determination of plasma fibronectin can reflect theseverity of the illness and the prognosis of the patients with SVH.