Abstract: Within the new family of nanomaterials,carbon nanotubes（CNTs） have attracted intensive interests in the field of biomedicine because of their unique nano structures.Functionalized carbon nanotubes（f-CNTs） possess unique distinguished function and strong ability to translocate through plasma membranes and low toxicity,which provide a wider prospect for the development of biosensor and make their applications in drug and gene transfer systems being possible.Towards this subject,we review the recent domestic and international research developments of the applications of carbon nanotubes in biosensor and drug/gene delivery systems,and discuss their toxicity.