Recent studies show that differences in production performance of animals fed with cereals could not be explained only with differences in nutrient content and digestibility; when digestibility kinetics is taken into account, the precision of nutritional evaluation of feeds is considerably improved. Although high moisture corn silage is widely used feed in pig fattening, there is no data about its starch digestibility kinetics in the available literature. Furthermore, there is no data regarding the effect of storage time on changes in starch digestibility kinetics of Croatian hybrids. The aim of this research was to determine changes in in vitro ileal digestibility of high moisture corn silage. Spontaneous fermentation of hybrid Bc 344 grain was performed in vacuum bags, while sampling was performed by the opening of bags representing 0, 15, 48, 98, 182, 274 and 364 days of storage. In vitro digestibility procedure was done according to the first order kinetics mimicking digestion in stomach and small intestine. The extent of starch digestion was determined after 0,25, 0,5, 0,75, 1, 2, 3, 4, 5 and 6 hours of incubation and in all samples free sugar and total starch contents were determined for digestibility rate calculations. Free sugar content decreases with increasing storage time while variations in starch content were within 3%. Dry matter digestibility linearly increased from 80,84 to 88,26% with increasing storage time. A 62,74% of starch was digested in the first hour of digestion, and after 4 hours of digestion all starch was digested in samples stored more than 15 days. Starch digestibility rate increased with increasing storage time of high moisture corn silage which can be described with linear and quadratic equations.