Abstract: The in-situ growth of carbon nanotubes (CNTs) on the carbon fiber can effectively avoid the uneven distribution of CNTs and exploit the advantages of carbon fiber and carbon nanotubes to the full,which play an important role in enhancing the interfaceproperties of the carbon fiber reinforcedpolymer (CF/EP).The surface of carbon fiber were modified and loaded with catalysts,and then the multy-walled carbon nanotubes (CNTs) were in-situ solid phase grown on the surface of carbon fiber with the assistance of thiophene.The carbon fiber obtained by this method can not only avoid the entanglement and uneven distribution of the CNTs in CNTs-CF/EP,but also enhance the interlaminar properties of CNTs-CF/EP due to the carbon source of synthesized CNTs mainly from the treated carbon fiber with the high surface bonding strength between the carbon fiber and the CNTs.The effects of the catalyst concentrations on the morphologies of growth CNTs and the performances of carbon fiber were investigated by SEM,XRD,FT-IR and other measurements.The results show that the synthesized CNTs can uniformly distribute and firmly bond on the surface of carbon fiber with the proper catalyst concentration of 0.2 mol·L^-1.The mechanical properties of the carbon fiber decrease a little.