In our previous research, a series of PHB/PEG multiblock copolymers (Fig. 1) have been successfully synthesized and their properties have been characterized. In this study, we adopted the soil suspension to assess their biodegradability in detail. Meanwhile, two major components in BHG copolymers, PHB and PEG, are both crystallizable, which lead to their crystallization behavior may be different from those of other multiblock copolymers. So the crystallization behavior of these kinds of copolymers was also investigated by DSC and WAXD in this study.