In this work, a bio-based copolyester with good mechanical properties was synthesized andcharacterized in terms of structure, main properties and biodegradability Determining the chemicalstructure of such materials is important to understand their behavior and properties. Performingan extraction of insoluble cross-linked polymer using di erent solvents allowed us to analyze howthe polymer behaves when subjected to di erent chemical environments, and to obtain solublesamples suitable for more in-depth analysis. Chemical structure of poly (xylitol sebacate-co-butylenesebacate) was determined by a 1H NMR and FTIR analysis of both prepolymer gel sample andsamples obtained by extraction of cross-linked polymer using di erent solvents. Block structure ofthe copolymer was confirmed by both NMR and DSC. Gel fraction, swelling value, water contactangle, and mechanical properties were also analyzed. Biodegradability of this material was confirmedby performing enzymatic and hydrolytic degradation. Synthesizing sugar-alcohol based copolyesterusing three monomers leads to obtaining a material with interesting chemical structure and desirablemechanical properties comparable to conventional elastomers.