Summary: Acrylonitrile butadiene rubber (NBR) has been blended into biodegradable Poly(butylene succinate) (PBS). The PBS/NBR blends with ratios of 100/0, 90/10, 80/20, 70/30, 60/40 and 50/50 by weight were prepared in an internal mixer. Dicumyl peroxide (DCP) was used for vulcanization of the NBR phase in the blends. Mechanical properties and thermal stability as well as morphologies of pure PBS, vulcanized NBR and PBS/NBR blends were investigated. The blends provide much higher elongation and impact strength than the pure PBS. The PBS/NBR blend with a ratio of 90/10 shows superior result to toughness, and gives comparable results for modulus and tensile strength at break with respect to the pure PBS. Morphology observation reveals the compatibility of the PBS/NBR blends, especially in the blends with 10-30 wt% NBR content. Moreover, thermogravimetric analysis (TGA) result shows that thermal stability of PBS is enhanced when NBR is added.