Increasing cases of enviromental pollution caused by plastic waste are causing people to do research looking for alternative raw materials plastics manufacturing. Durian seeds that become waste, is proved to have a high starch content that can be used as a substitute polymer in the manufacture of bioplastic. Strach is first extracted from the durian seeds combined with Low Density Polyethylene to create biodegradable plastics. Durian seeds starch based plastic are compared with sago starch based plastic and buried in the soil for 5 weeks. Reduced weight, mechanical strenght, and SEM analysis are perfomed to determine the level of degradation of bioplastics. Bioplastic from durian seed starch appeared darker than bioplastics made from sago starch, due to its protein content which induces browning reaction. Bioplastics buried in the soil are losing its weight due to a process of degradation by microbes in the soil. SEM analysis which a magnification of 1000x, shown that the surface of bioplastic have some space which water absorbed and caused increasing of weight. Durian seed starch based plastic show different physical and mechanical characteristics to sago starch based plastic. Durian seed starch based plastic have a lower degradation rate than sago starch based plastic. Durian seed starch and sago starch are potential to be developed as a bioplastic materials.