Mook, a traditional gel food in Korea, has been made from mainly acorn, buckwheat, and mungbean starches (Mook Starches). Corn, rice, wheat starches (Non-Mook Starches) are not used due to their weak gelation power. In order to know the effects of properties of starch on gelation, some physicochemical properties, molecular structure, and starch lipid of these six starches were investigated and compared with gel hardness. Both amylose content and gel hardness of starches were in order of mungbean, acorn, buckwheat, wheat, corn, and rice and these two parameters showed a very good correlation (r=0.95). The amyloses of Mook Starches had larger molecular size (${overline}D.P._{n}=1,080{sim}1,580;vs;670{sim}1,120$ for Mook Starches and Non-Mook Starches, respectively), more average number of chain ($2.9{sim}5.4;vs;1.7{sim}2.5$), and shorter average chain length ($290{sim}390;vs;390{sim}450$) than those of Non-Mook Starches. Also, Mook Starches had longer average chain length ($22.2{sim}22.6;vs;18.9{sim}21.3$) of amylopectin and less starch lipid content ($0.12{sim}0.49;vs;0.68{sim}1.26%$) than Non-Mook Starches. These properties had good correlations with gel hardness (r=0.76-0.84). Consequently, the gelation power of Mook Starches was thought to be derived from their high amylose content and other properties of starches.