The CS/PVA/Fe3O4 nanocomposite membranes with chainlike arrangement of Fe3O4 nanoparticles are prepared by a magnetic-field-assisted solution casting method.The aim of this work is to investigate the relationship between the microstructure of the magnetic anisotropic CS/PVA/Fe3O4 membrane and the evolved macroscopic physicochemical property.With the same doping content,the relative crystallinity of CS/PVA/Fe3O4-M is lower than that of CS/PVA/Fe3O4.The Fourier transform infrared spectroscopy (FT-TR) measurements indicate that there is no chemical bonding between polymer molecule and Fe3O4 nanoparticle.The Fe3O4 nanoparticles in CS/PVA/Fe3O4 and CS/PVA/Fe3O4-M are wrapped by the chains of CS/PVA,which is also confirmed by scanning electron microscopy (SEM) and x-ray diffraction (XRD) analysis.The saturation magnetization value of CS/PVA/Fe3O4-M obviously increases compared with that of non-magnetic aligned membrane,meanwhile the transmittance decreases in the UV-visible region.The o-Ps lifetime distribution provides information about the free-volume nanoholes present in the amorphous region.It is suggested that the microstructure of CS/PVA/Fe3O4 membrane can be modified in its curing process under a magnetic field,which could affect the magnetic properties and the transmittance of nanocomposite membrane.In brief,a full understanding of the relationship between the microstructure and the macroscopic property of CS/PVA/Fe3O4 nanocomposite plays a vital role in exploring and designing the novel multifunctional materials.