Abstract: Bacterial spores have very rigid structure and in general they are very difficult to inactivate. But most of bacterial spores treated by high voltage pulsed electric field(PEF) can be inactivated. The efficiency of the treatment relates to PEF parameters while treating the media with bacterial spores. The inactivation rate of spores increases with increasing total PEF treatment time. The inactivation rate of spores is affected by both pulse frequency and pulse duration time.