Macroglobulinemia was first described by Waldenstr m' s in 1944. It is charaterized by heavy accu mulation of monoclonal IgM in the plasma and infilration of plasmacytoid lymphocyte in bone mar row, lymph node, liver, and spleen. Its clinical manifestations include fatigue, weight loss, bleeding diathesis, hepatomegaly, lyphadenophathy, occular changes and neurologic symptom. Hyperviscosity syndrome may develop as a complication of macroglobulinemia. We have experienced one case o Waldenstr m' s macroglobulinemia with portal hypertension.