Abstract: The characteristics of front-end light, a key problem in EFISI(Echelon-Free Induced Spatial Incoherence), is analyzed in this paper, and a new type partially coherence light source is researched here. According to electrooptical properties of nematic liquid crystal, two type liquid crystal are used as scattering materials to carry out the experimental study of partially coherence light source designed for EFISI. The relationship between applied voltage and energy transmittivity, uniformity, coherence of scattering light is obtained. Results show that both intensities and uniformity of scattering light can be improved, at the same time coherence can be decreased through changing the applied electrical field. So the partially coherence light source can be approached