The purpose of this study was to analyze the effect of adding polypropylene (PP) to sago starch thermoplastic (TPPS) combination of polypropylene grafting maleic anhydrous (PP-g-MA) on density values, degradation tests, and morphological analysis. The thermoplastic mixture of sago starch/polypropylene/polypropylene maleic anhydrous was carried out using the blending method using an internal mixer. Based on the research results, the addition of polypropylene can reduce the density value, and the rate of degradation in freshwater, seawater, and soil storage media. The surface morphology indicates the presence of the dispersed phase (Polypropylene) which is evenly distributed over the entire surface of the matrix (TPPS). there was a shift in wave number in the O-H and CO groups on the bioplastic composite in the FTIR test.