A 36-year-old woman was hospitalized because of nephrotic syndrome. On admission, laboratory studies revealed total protein 5.9g/dl, total cholesterol 381mg/dl, urine protein 2-4g/day, C3 68mg/dl(90-185mg/dl) and the immunological tests showed that antinuclear factor, anti-DNA antibodies and the LE cell phenomenon were positive. Renal function was within normal range. After admission, renal biopsy was done. Light microscopic finding showed diffuse membranous glomerulonephritis, and vacuolization of epithelial cells. Immunofluorescent microscopic finding showed a granular specific staining for IgG, IgM, C3 and C1q along the capillary loops. Electron microscopic finding showed subepithelial and subendothelial dense deposits, and visceral epithelial cell cytoplasm containing osmiophilic multilamellar lipoid bodies. In the studies of the enzyme activities, the patient's fibroblast extract demonstrated a partial deficiency of alpha-galactosidase, and urine ceramide trihexoside was positive. But the patient's leukocyte extract did not demonstrate a deficiency of alpha-galactosidase. So Fabry's disease associated with lupus nephritis was diagnosed. It seems that the case of Fabry's disease which is an X-linked disorder caused by deficiency of the lysosomal enzyme alpha-galactosidase, associated with lupus nephritis, is extremely rare.