The experimental investigation on a liquid-liquid spray process by dispersing water in corn oil was conducted.The drop formation in the spraying process was observed through analyzing photographs from camera.The observation showed that with increase of electrostatic voltage,the drop formation presented a dripping mode as well as cloudy spraying mode in turn and the drops displayed different characteristics in pattern and movement under two kinds of modes.The existing condition and the characteristics of two modes were presented.The quantitative analysis of spraying droplet diameter distributions was performed at different voltages by means of particle image analyzer and the theory of spraying droplet distribution.The result showed that for liquid-liquid electrostatic spray,the droplet size distribution could be mathematically described by Rosin-Rammler distribution.With increase of voltage,the droplet became fine in size and uniform in size distribution.Comparing with water-in-gas spray,the probability density function curve for droplet size distribution was not symmetrical with respect to its peak value,viz,the diameter distribution for the relatively smaller droplets was narrower than that for other larger droplets.With increase of voltage,the distribution for larger droplets became narrow and the curve shape of probability density function became nearly symmetric.