In this research, starch-based biocomposites films reinforced with San Pa Tong sticky rice microcrystalline cellulose and plasticized with glycerol were prepared. Microcrystalline cellulose from San Pa Tong sticky rice (SPT-MCC) were extracted by alkaline delignification process, bleached with hydrogen peroxide and hydrolysis with sulfuric acid, respectively. Starch-based biocomposite films reinforced with San Pa Tong sticky rice microcrystalline cellulose (SBF-SPT-MCC) were prepared by solvent casting technique. Microcrystalline cellulose content was varied from 0-60 %w/w based on starch content. Effect of microcrystalline cellulose content on thermal and mechanical properties of the composite film were studied. Biodegradation of biocomposite films were investigated by soil burial test methods for 8 days. Biodegradation of biocomposite films were studied compared with the degradation of 3 types of commercial plastic bags. The result showed that thermal stability of biocomposite films decreased with the increasing of microcrystalline cellulose content, while the tensile strength and Young’s Modulus of biocomposite films increased with the increasing of microcrystalline cellulose content. Starch-based biocomposite film completely decomposed within 8 day. For all 3 types of commercial plastic bags, no degradation occurred within the testing period.