The recent development of modification of bacterial poly (β-hydroxybutyrate) (PHB) by chemical and physical methods is reviewed in this article. The physical modification here is referred to simple blending

while the chemical methods include Reactive Polymer Blending (RPB) and modification based on PHB macromers due to both of them involving chemical reactions. Of all simple PHB blend systems

totally degradable blends are quite different from disintegrated blends. Applications of totally degradable blends are ultimate trends to resolve the environmental problems in a long run

while at present their practical applications mainly focus on biomedical fields. The miscibility

thermal behavior

crystallinity

mechanical and degradation properties are systemically summarized in this article. Furthermore

it has been pointed out RPB is a useful method to improve miscibility of PHB blends

and the modification based on PHB macromers and the interpentrating technique are two effective ways to modify PHB and construct newly functional biomedical materials. These researches represent the new trends of PHB modification work.