Biodegradable polymer was prepared from natural rubber mixing with chitosan by two-roll mills technique. The chitosan was obtained from chitin through deacetylation reaction at 100 O C for 60 min. The effect of various amounts of chitosan (0, 5, 10, 15 and 30 phr) and embedding time in soil (2 and 6 months) on physical properties of polymer before and after exposure to soil burial was investigated. It was found that physical properties of polymers decreased with an increase in amount of chitosan and soil burial time. In addition, a decrease in physical properties of polymers after aging by heating, UV-light and moisture was more obvious than before aging.