This study was conducted to develop an optimal composite recipe for nutritional cookies containing beet powder. Flour was substituted with whole wheat flour containing germinated brown rice powder. The sensory optimal composite recipe was determined by making cookies containing two levels of beet powder (A) or butter (B) according to Central Composite Design (CCD) and by conducting the sensory evaluation and instrumental analysis according to Response Surface Methodology (RSM). Using CCD, the results of physical measurement for ten conditions with two variables were obtained. The values of lightness (L), redness (a), and yellowness (b) were in the range of 36.65~49.03, 22.15∼29.31, and 13.96~19.34, respectively. Lightness decreased significantly (P＜0.001) and redness increased significantly (P＜0.01) upon an increase in beet powder. The results of sensory evaluation showed very significant values in color (P＜0.05), texture (P＜0.05), flavor (P＜0.01), taste (P＜0.05), and overall quality (P＜0.05), whereas those of the instrumental analysis showed significant values in lightness (P＜0.001), redness (P＜0.01), spread ratio (P＜0.01), and hardness (P＜0.05). As a result, the optimal sensory ratio of beet cookie was calculated for beet powder 7.75 g and butter 77.88 g.