Transient disturbances are often encountered in the field of power quality research. It is something of significance to quickly and accurately locate these disturbances. This paper presents a method for locating transient disturbances by means of Hilbert transform combined with backward difference in the time domain. The envelope of the disturbance signal is detected via Hilbert transform， then the disturbance signal is located by using backward difference. The experimental results and the performance analysis show that the method possesses the merits of simplicity， speediness and accuracy， and meets the requirement of the real-time cases.