The subjects here were patients (two males and a female) with the severe acute Guillain-Barre Syndrome admitted to our hospital between September 1987 and December 1988. One case was treated with a double filtration plasmapheresis and two cases were with a immunoadsorption. Of the two extracorponeal thrapeutical methods, the clinical efficacies seemed not to be different however biochemical and serological laboratory data showed prominent differences. For instance the large molecular substances in blood; immunoglobulins, coagulating factors and albumin were reduced in plasma levels by the double filtration plasmapheresis, but not or less by the immunoadsorption. Considering the expectable side effects of the two methods, it may say that the immunoadsorption should be applied as a beneficial extracorponeal method for the acute Guillain-Barre Syndrome.