The growth inhibitory effect of wheat grain, fermented wheat grain products, red pepper powder and kochujang was examined in AGS human gastric adenocarcinoma cells. The kochujang samples were prepared by mixing red pepper powder and each fermented wheat grain products, such as first fermented wheat grain (FFWG), second fermented wheat grain (SFWG) and final fermented wheat grain (FiFWG). The methanol extract of FiFWG showed the highest growth inhibitory effects. In order to investigate the effects of fermented wheat grain products at each stage of fermentation on anticancer activity, the kochujang prepared with red pepper powder and each of FFWG, SFWG and FiFWG were fermented until reaching pH 5.1. The kochujang adjusted to pH 5.1 by fermentation increased the growth inhibitory effect; however, the kochujang prepared with FiFWG showed the highest effect. Increased fermentation time increased the growth inhibitory effect of kochujang when prepared with FiFWG. These results suggested that the anticancer effect of the kochujang on the gastric cancer cells was affected by the fermentation periods of the wheat grains. The well-fermented end products of the wheat grains seem to be one of the major components that showed anticancer activity of kochujang.