We investigated the relationship between hepatitis B and membranous glomerulonephritis and progress of disease after treatment with cyclosporine A. Twenty seven patients were reviewed retrospectively about clinical manifestations, laboratory findings, pathologic findings and progress of disease after treatment with steroid alone or steroid plus cyclosporine A. The male to female ratio was 3.5:1 and mean age was 8.9 years ranged from 2.8 to 16.9 years. The common clinical manifestations were edema(81%), asymptomatic proteinuria(19%) and micro- or macroscopic hematuria(78%). In viral marker studies, seventeen patients(63%) showed positive HBsAg and among them, 16 patients(59%) showed positive HBeAg. Eleven patients treated with steroid and cyclosporine A showed complete remissions and 12 cases among 16 patients treated with steroid alone showed complete remissions. In conclusion, sixty three percents of children with membranous glomerulonephritis have strong association with HBsAg. The most common clinical manifestation was edema. Patients treated with cyclosporine A and steroid showed better results than patients treated with steroid alone(P=0.03).