Silicate layered/polymers nanocomposites have recently been the focus of both academic and industrial attention. Biodegradables polyesters polymers have attracted more and more interest due to increasing environmental concern and decreasing fossil resources. Poly(butylene succinate) PBS is one of the most promising polymers in the family of synthetic biodegradable polyesters and can be processed in various potential applications. However, its low molecular weight and lacks mechanical strength compared with conventional plastics often limit the use of this polymer in some applications. These properties can be improved to achieve compatibility with thermoplastic processing, manufacturing and end-use requirements by the addition of small quantity of an environmentally nano-reinforcement. In this study, Poly (butylene succinate)/clay nanocomposites with different contents of organomodified Moroccan clays (3CTA+-BDT) have been prepared via in situ polycondensation approach of 1,4- Butandiol with succinic anhydride in presence of catalyst based on Bismuth (BiCl3). The PBS/Organoclay nanocomposites were characterized by IR, NMR, X-ray diffraction (XDR), Scanning electron microscope (SEM), thermal properties, thermal conductivity and water vapor sorption. The authors thank the financial supports of the Moroccan Academic of Sciences and techniques-CSIC project, and also to Erasmus Mundus program (Battuta project) financed by the European Commission between Riga Technical University and University Cadi Ayyad of Marrakech.