The purpose of this study was to investigate mechanical and biodegradation properties of bioplastic from pure cornstarch (with no additional reinforcing components). The following fabrication procedure was done: (1) diluting cornstarch in water, (2) making homogeneous mixture of the diluted cornstarch, glycerol, and acetic acid by heating at less than 100ºC, (3) molding process, and (4) drying process to get a solid bioplastic. The present bioplastic had good biodegradability properties, degraded easily within 2-week soaking in water, confirmed by the weight loss and appearance of fungi on its surface. Good mechanical performance was obtained although it is still low compared to the standard bioplastic in moderate grade. Indeed, additional reinforcing components (e.g., co-polymer or additive) is required for improving the mechanical properties.