This study was to compare the effects of soy hot water extract, soy slurry, defatted soy flour, soy protein concentration and soy protein isolate on the quality of Busuge Base. In Busuge Base preparation the addition of soy products, in general, showed the improvable effect in the quality of Busuge Base. Among them the soy slurry was especially effective in volume increasing, hardness and panel score, and the soy protein isolate was effective in the protein fortification of Busuge Base. In addition, the qualify of Busuge Base was best when soy slurry and soy protein isolate were jointly used. In this case, the adequate amount of soy protein isolate was about 10%.