Abstract: The microbial poly(β–hydroxyalkanoate)（PHA）is a biodegradable and biocompatible thermoplastic polyester. It has attracted much attention as tissue engineering scaffold. But the drawbacks of the PHA restrict its wide application，such as its hydrophobicity，low bioactivity，and the difficulty in controlling its degradation. The recent modification developments of PHA are reviewed. The properties of PHA were improved after modification，which would widen its application in the fields of tissue engineering and medical materials.