Much attention has been given to the role of safflower (Carthamus tinctorius L.) seed in preventing and treating osteroporosis recently. Although numerous studies were done on effects of safflower oil, no attention was given to the role of dietary fiber of safflower seeds. This study was aimed at investigating physiological significance of defatted safflower seed as a source of dietary fiber. Sprague Dawley female rats were assigned one of 5 groups: ovariectomized control (Ovx-control) group and ovariectomized rats 15% (Ovx-ss15) and 30% defatted safflower seed (Ovx-SS30), sham-operated (Sham) group and a normal group. Cholesterol was supplemented to all diets at 0.5% except the normal diet. Ovariectomized rats were pair-fed isocalorically to the Sham group. Ovariectomy caused heavier body weight, but feeding 30% safflower seed brought back to the level of Sham group. Activities of disaccharidases of jejunal mucosa were significantly lowered in Ovx-control group compared to those of Sham, and supplementation of safflower seed tended to increase the activities. Fecal weight of Ovx-SS15 and Ovx-SS30 were almost twice as those of Ovx-control Sham. Propionic acid and butyric acid concentrations per g of feces of Ovx-SS15 and daily excretion of these fatty acids were significantly increased as compared to those of Sham and Ovx-control. In concentration defatted safflower seed supplementation significantly increased fecal bulk and short chain fatty acid production in large intestine of rats.