This paper describes the application of phase difference method for locating partial discharge （PD） in power cables from single-end measurement. The phase difference between the direct and reflected waves of a PD pulse at various frequencies can be obtained from the cross Fourier spectral density function. After implementing a phase unwrapping algorithm, the defect in the cable can be located. Unlike the time-domain reflectometry （TDR） methods, this technique does not need to estimate the arrival time of the PD signals. Laboratory experiments on a model of a 3.3 kV, 50 m underground cable have been carried out. The experimental results indicate that the proposed technique has better location accuracy compared to the commonly used time-domain methods.