Styrofoam is a trade name for Expanded Polystyrene (EPS) which is composed of styrene monomer. Styrofoam is widely used as food packaging because it provides good insulation in maintaining food conditions and its lightweight nature is suitable for storing large quantities of food to keep it safe without adding weight. However, styrofoam has a negative impact on health and the environment because it is difficult to recycle and difficult to degrade naturally so it is necessary to find an alternative environmentally friendly foam (biodegradable foam). In this study, biodegradable foam was prepared from jackfruit seed starch and sugarcane bagasse by thermopressing method. Biodegradable foam with a composition of jackfruit seed starch and sugarcane bagasse of 70:20 had the highest compressive strength, which was 13.63 Mpa, and with the addition of 10% chitosan the compressive strength increased to 52.2 MPa. Meanwhile, the water absorption capacity of biodegradable foam with a composition of jackfruit seed starch and sugarcene bagasse of 70:20 was 48% and with the addition of 10% chitosan, the water absorption capacity decreased to 16%. The biodegradation rate of biodegradable foam with the addition of 10% chitosan was slightly lower than that of biodegradable foam without the addition of chitosan. The results of the SEM analysis of biodegradable foam with the addition of 10% chitosan appeared to have a denser and more homogeneous structure compared to biodegradable foam without the addition of chitosan