This paper proposes a method of faults location for transmission lines by using broadband chaotic signals,which is experimentally demonstrated with a chaotic semiconductor laser. Chaotic signal is obtained by converting the chaotic light from the chaotic laser diode,and divided into two signals,one serving as probe signal and the other serving as reference signal. Faults are located by correlating the echo of probe signal with the reference one. The spatial resolution is determined by the time resolution of correlation curve. Experimental results show that 7.5 cm resolution can be readily achieved by common laser diode.