Conducting polymer could be used as molecular wires for transferring electrons directly between bioactive materials and electrode materials for its good conductivity,and is considered to be a new type of material for fabrication of biological sensors.With some excellent features such as electrical conductivity,biocompatibility and easy immobilization,polypyrrole(PPy)has a good application prospect in the immobilization of bioactive components in sensors.In this paper,the latest research development on biosensors based on PPy is reviewed.The synthesis methods of PPy together with its doping mechanisms were firstly introduced.The various methods for the immobilization of biocomponents on PPy and the fabrications of biosensors based on PPy were described in detail,together with the advantages and disadvantages of the immobilization methods of biocomponents to PPy.Especially,the latest applications of PPy in the field of immunosensors were reviewed.The development direction of conducting PPy biosensors in the future was also put forword.