AbstractSolubility, swelling power, viscosity, alkali number and ferricyanide number were estimated in the starch isolated from both irradiated air‐dried and moist corn grains. An increase in solubility, alkali number and ferricyanide number and decrease in relative viscosity were found in starch isolated from irradiated air‐dried as well as moist corn grains as the dose level was raised. The swelling power increased up to 2 megarad, then decreased rapidly. Infrared analysis revealed an additional absorption band which arises from a new methylene group at 5 megarad. An increase in amylose percentage concomitant with a decrease in amylopectin percentage was found as the radiation dose was increased up to 2 megarad. Above 2 megarad, the opposite was found. The chain length of amylose and amylopectin showed a progressive decrease as the irradiation dosage was rai