In this article, biodegradability of Low Density Polyethylene (LDPE) with potato starch was studied. Polyethylene grafted maleic anhydride (PE-g-MA) used as a compatibilizer. Samples with different levels of potato starch (as10%, 20%, 30% and 40%) with constant amount of PE-g-MA as 5% were prepared. In all samples amount of compatibilizer are the same. The effect of potato starch content on the thermal properties of blend studied with a differential scanning calorimeter (DSC). Result show with increasing potato starch content, crystallization decreased. The biodegradation of blends was studied with soil burial and exposure to mould growth. Biodegradation determined by weight lose, the change in tensile properties of the sheets and mould growth. The results showed that with increasing potato starch content biodegradability of blends increased. Biodegradation of the samples due to soil burial after 8 months revealed that the weight of the blends was decreased by increasing the potato starch level.