The renoprotective activities of white ginseng radix and rootlet were compared in spontaneously hypertensive rat (SHR) with diabetes. During oral administration of white ginseng radix (Ginseng Radix Alba, GRA) and white ginseng rootlet (Ginseng Radix Palva, GRP) for four weeks, arterial blood pressure and blood glucose levels were determined at every 10 days. In both GRA- and GRP-treatment groups, arterial blood pressures started to go down after 10 days of administration and maintained throughout the study period. After four weeks administrations of GRA and GRP, diastolic blood pressures were significantly decreased with 17% and 9%, respectively. GRA treatment also decreased blood glucose levels after 10 days of administration when compared with diabetic SHR group. At the end of the experiment, serum creatinine (Scr) and blood urea nitrogen (BUN) were not significantly different between the groups, except 62% higher value of BUN in diabetic SHR group when compared with SHR group. In the diabetic SHR group, the excretion of urinary albumin was increased significantly when compared with SHR. The level of urinary albumin in GRA treated group was markedly reduced when compared with diabetic SHR group (67.8⁑4.7 vs. 131.3⁑13.5 mg/24 h). To examine the effects of ginseng radices on an overt diabetic nephropathy, index of kidney hypertrophy and transforming growth factor-β1 (TGF-β1) protein levels were evaluated. The glomerular and tubular cells stained positive for TGF-β1 seemed to be more abundant in diabetic SHR than in those with SHR, and GRA treated rats showed somewhat less TGF-β1 protein in glomerular and tubular cells when compared with diabetic SHR. Our results suggest that GRA might be a useful antihypertensive and antidiabetic agent with renoprotective effect.