Three degradable polymer materials such as starch-polyethylene (PE) binary blends, PE containing starch and a photoactivator, and PE containing starch and a photoactivator which was coated with gelatin were prepared and their degrees of photodegradation and/ or photodegradation after biodegradation were investigated. The addition of the gelatin-coated ferric salt in PE extended the induction period of degradation and accelerated photodegradation after the removal of coating material by biodegradation. This result suggested that the degradation rate of PE could be controlled if more powerful photoactivators and/or coating material are developed and their contents are optimized.