The effects of raw and processed small black soybean powders on dietary fiber content and gastrointestinal function in rats were investigated. The crude oil, protein, and ash contents of raw small black soybean powder were not significantly different from those of processed small black soybean powders. The germination process increased soluble and insoluble dietary fiber contents significantly, as compared to raw small black soybean powder. The germinated small black soybean powder diet led to a significantly different food intake than the basal diet in both normal and loperamide-induced constipated rats. The body weight gains of the experimental groups, however, were not significantly different from that of the basal diet groups for both the normal and loperamide-induced rats. The gastrointestinal transit times and fecal weights for normal and loperamide-induced rats consuming the processed small black soybean powder diet were significantly different from those on a basal diet. These results suggest that the processes of cooking and germinating the small black soybean might contribute to acceleration of fecal excretion in both experimental normal and constipation model rats.