A type of nano chitin whisker (NCW) reinforced poly (vinylidene fluoride) (PVDF) membranes were prepared through non-solvent induced phase separation process, which exhibited significant improvement of mechanical properties, water permeability and especially antifouling property. The pure water flux of resulting composite membranes with 52% improvement in mechanical properties reached 392 L m(-2) h(-1) in comparison to 184 L m(-2) h(-1) for pure PVDF membrane (without NCW addition), while flux recovery ratio was significantly increased from 13% for pure PVDF membrane to 92% for PVDF/NCW composite membrane because of the perfect entrapment of NCW in PVDF matrix, which resulted in ideal morphology, i.e. decreased surface mean pore size with narrow pore size distribution, increased porosity, hydrophilicity and surface roughness, where the semi-closed pores of pure PVDF membrane are changed to interconnected pore structure of composite membrane. These results were better than those reported in the literature, suggesting a promising competency of PVDF/NCW composite membrane in wastewater treatment and water purification. (C) 2015 Elsevier B.V. All rights reserved,