Poly (vinylidene fluoride) blend membranes were prepared by melt-blending the ternary mixture of PVDF/SiO2/dibutyl phthalate (DBP) in combination of thermally induced phase separation (TIPS). The results of water permeability and instrumental analysis illustrated that micro-size SiO2 and DBP concentration obviously affected the performance and structure of the PVDF membranes. It was found that water flux effect and tensile strength increased with micro-particle content, but it reached limit content above which water flux did not increase. The surface and cross-section of the membranes were characterized by AFM and SEM depended on SiO2 weight fraction. The results showed that the morphology of PVDF and the formation of the spherulitic morphology can be disturbed by SiO2. Porosity and the water flux of the blend membrane increased, the membrane strength decreased with increasing DBP concentration. (C) 2010 Elsevier B.V. All rights reserved.