Abstract: This paper describes methods for the measurement of the resistivity of different carbon fibers ( T300 and T800 in the T series as well as M40J，M55J and M60J in the MJ series) ． Two methods，linear sweep voltammetry and alternating-current impedance，were used to determine the value of the electrical resistivity of every sample．The effect of the gauge length on the resistivity of the carbon fibers was evaluated． The results showed that there is no significant difference between the two methods when using a digital micro-ohmmeter． More accurate values of resistivity can be obtained by elimination of the contact resistance after a fitting process for the resistance of different gauge length samples．