The influence of content and aspect ratio of whiskers, calcium carbonate and aluminum borate, on the morphology evolution of liquid crystalline polymer (LCP) was investigated in polysulfone (PSF) matrix. The study showed that the deformation of LCP droplets was significantly promoted by adding whiskers into PSF/LCP blends, and the longer whisker produced a more pronounced fibrillation effect. The analysis of flow field and elasticity of system showed that the addition of longer whiskers increased the elasticity of materials more efficiently and enhanced the vortex in the converging flow area at the entry of capillary, which resulted in an increase of the elongational stress and promoted the formation of longer LCP fibrils in PSF/whisker system.