Rate of decreasing levels of total sugar and starch content in rice plants during complete submergence could be considered as an indicator of submergence tolerance as revealed through repeated experiments with two submergence tolerant and two susceptible varieties. Younger the seedlings (7 days), quicker are depletion than in older seedlings of 10 and 15 days. Drastic reduction is thus prominent under prolonged submergence period (15 days) than 7 or 10 days of complete submergence. Susceptible varieties show maximum decrease in starch and sugar content than resistant varieties.