Rheological, thermal, and mechanical properties for blends of synthetic biodegradable aliphatic polyester (BDP) and poly(epichlorohydrin) (PECH) were examined. The synthetic BDP was a copolymer synthesized from the polycondensation reaction of aliphatic glycols and aliphatic dicarboxylic acids. From differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis, we confirmed the BDP and PECH blends were miscible. The DSC results suggest that the degree of crystallization of BDP in blends decreased sharply as PECH content increased. We also show a great increase of both elongation at the break point and tensile impact strength increase with PECH content. From the static and dynamic rheological experiments, we found that shear viscosity increases with PECH content, which is consistent with the storage moduli increasing with PECH content. This suggests that PECH acts as a diluent for BDP, and these two polymers are compatible in the melt state. The storage moduli of the BDP homopolymer are lower than that of blends.