Impact of heat-moisture treatment( HMT) on digestibility of waxy corn starch in their gelatinized states were studied. Digestibility was evaluated by determining rapidly digestible starch, slowly digestible starch,resistant starch of waxy corn starch after HMT. Results show that the content of rapidly digestible starch dramatically decreased,the content of slowly digestible starch and resistant starch markedly increased when the water content,temperature and time of HMT increased.