Corn starch-based films with trimethyilene glycol (1,3-propanediol) as plasticizer were prepared with the castingtechnique and subject to acid hydrolysis (HCl 1.0 M) at 20 oC. The film degradation was monitored by changes in surfacemorphology, crystallinity, thermal properties and surface wettability. In the first two days, the hydrolysis showed lowadvance to subsequently exhibit a huge increase of the reaction rate. It suggested that surface erosion is the main mechanisminvolved in the film degradation. XRD showed the presence of poly-1,3-propanediol, attributed to condensation reactionof plasticizer in acidic conditions. Thermal analysis showed two endothermic peaks at 110-120 oC attributed to meltingof crystallized amylopectin and to a lesser extent co-crystallized amylose and amylopectin. The temperature of thesepeaks was not affected by hydrolysis time, supporting the idea that hydrolysis reactions are constrained to the film surface.Contact angle measurements indicated a significant decrease of hydrophobicity caused by fractionation of starch chains.