The main objective of this study was to investigate whether orally administered Korean grain larvae ethanol extract (GLE) had a bifidogenic effect in normal rats. Male Sprague-Dawley rats were divided into a negative control group (CO) and GLE orally administered (5.0, 7.0 and 9.0 mg/100 g body weight) groups. Thymus and spleen weights dosedependently increased by 128.58 percent and 128.58 percent, respectively, but abdominal fat decreased by 19.18 percent after GLE administration compared with that in the CO group (p less than 0.05). Serum triglycerides, total cholesterol, low-density lipoprotein cholesterol, and glucose decreased by 30.26 percent, 7.33 percent, 27.20 percent, and 6.96 percent, respectively, whereas highdensity lipoprotein cholesterol increased by 129.93 percent in the GLE groups compared with those in the CO group (p less than 0.05). IgG, IgM, IgA in the GLE groups increased 203.68 percent, 181.41 percent, and 238.25 percent, respectively, compared to that in the CO group (p less than 0.05). Bifidobacteria and Lactobacillus increased by 115.74 percent and 144.28 percent, whereas Bacteroides, Clostridium, Escherichia, and Streptococcus decreased by 17.37 percent, 17.46 percent, 21.25 percent, and 19.16 percent, respectively, in the GLE groups compared with those in the CO group (p less than 0.05). Total organic acids, acetic acid, and propionic acid increased by 151.40 percent, 188.09 percent, and 150.17 percent, whereas butyric acid and valeric acid decreased by 40.65 percent and 49.24 percent, respectively, in the GLE groups as compared with those in the CO group (p less than 0.05). These results suggest that Korean GLE improves the bifidogenic effect by increasing cecal organic acids and modulating gut microflora via a selective increase in Bifidobacterium in normal rats.