Fifty rice varieties were tested for alkali digestibility of milled rice grain at four different KOH levels, and twenty - four varieties selected were tested again for alkali digestibility at different degrading times and KOH levels. Gelatinization rate at several heating times and heating temperatures, and water absorption rate at 21℃ and 77℃ water temperatures were observed using rice samples of twenty - four varieties to clarify the relationship between alkali digestibility response, gelatinization rate and water absorption rate. Varietal difference of ADV in Japonica and Tongil tye rices was biggest at KOH 1.2%, but it was better to test at KOH 1.2% and 1.4% levels to know the exact alkali digestibility response of rice varieties. Rice varieties tested could be classified into three groups, low, intermediate and high, based on their alkali digestibility response at four KOH levels, and most of Korean cultivated rice varieties were belonged to intermediate or high ADV group. Varietal variation was also found in alkali degrading response at different soaking times in alkali solution. Low ADV varietal group showed higher gelatinization temperature and needed longer heating time for complete gelatinization compared with intermediate or high ADV group. Same trends was found between intermediate and high ADV groups, but varietal variation in the same ADV group was also found in gelatinization temperature and heating time needed for complete gelatinization of rice grain. Water absorption rate of low ADV group was lower than intermediate or high ADV group both at 21℃ and 77℃ water temperatures, and intermediate ADV group showed lower absorption rate than high ADV group only in initial water absorption stage at 21℃.