In the present paper, the functional groups of PES/micro-nano cellulosecomposite membrane materials were characterized by Fourier transform infraredspectroscopy (FTIR). Also, changes in crystallinity in composite membranematerials were analyzed using X-ray diffraction (XRD). The effects of micro-nanocellulose content on hydrophilic property of composite membrane material werestudied by measuring hydrophilic angle. The images of support layer structure ofpure PES membrane material and composite membrane material were showed withscanning electron microscope (SEM). These results indicated that in the infraredspectrogram, the composite membrane material had characteristic peaks of both PESand micro-nano cellulose without appearance of other new characteristics peaks.It revealed that there were no new functional groups in the composite membranematerial, and the level of molecular compatibility was achieved, which was basedon the existence of inter-molecular hydrogen bond association between PES andmicro-nano cellulose. Due to the existence of micro-nano cellulose, thecrystallinity of composite membrane material was increased from 37.7% to 47.9%.The more the increase in micro-nano cellulose mass fraction, the better the vande waal force and hydrogen bond force between composite membrane material andwater were enhanced. The hydrophilic angle of composite membrane material wasdecreased from 55.8°to 45.8°and the surface energy was raised from 113.7 to123.5 mN?m-2. Consequently, the hydrophilic property of composite membranematerial was improved. The number of pores in the support layer of compositemembrane material was lager than that of pure PES membrane. Apparently, poreswere more uniformly distributed.高等教育学科创新引智计划项目(B08005)资助