Abstract: When the bar of rotor is broken,some feature frequency components will emerge in the cur-rent.The fault diagnosis system based on analyzing the current signal is of interest in this area.This di-agnosis system may be designed as a non-invasion type into the induction machine,which is simple in hardware and easy to sample the signals.This paper surveys previous works on rotor broken-bar fault di-agnosis by current signal analysis a nd concludes with a range of further issues that must be solved.