The electro-spraying process could be regular and periodic, consisting of the phases of initiation (meniscus, drop, or/and jet), pulsation, deformation and capillary separation in cycles. This paper presented an experimental study on the repetition frequency of drop or/and jet ejection from the capillary end with various spraying modes during an electro-spraying process of deionized (DI) water. Influences of operating parameters such as applied voltage, liquid flow rate, electrical conductivity (DI) and the number of emitters were considered. The time evolution of drop or/and je tinitiation, pulsation, deformation and separation from capillary tip or meniscus were captured and analyzed in detail under different spraying modes. The repetition frequency was calculated offline based on the time-resolved images captured by a high-speed camera. It was found out that, repetition frequency in the electro-spraying was highly affected by the electrical strength and depended ton spraying modes. The repetition frequency firstly increased and then decreased with an increase of applied voltages. Peak frequency and the applied voltage were related and both correlated to liquid flow rate. The repetition frequency was very sensitive to the applied voltage at low volume flow rate. Particular attention was given to the electro-spraying characteristics by single, double and three emitters. The similarity and difference were discussed.