AbstractComposite membranes for dialysis were prepared by a Loeb-Sourirajan (L-S) phase inversion process. After adding nanocrystalline cellulose (NCC), the ultrafiltration coefficient of the dialysis membrane could reach 48.37 L•m-2•h-1•mmHg-1. The clearance of lysozyme and urea could reach 70.25 % and 90.38 %, respectively. Simultaneously, the retention ratio of BSA could remain over 96%. Afterwards, in order to judge the hydrophilic nature of the dialysis membrane, the contact angle and surface energy were tested and calculated. And then the tensile strength and elongation ratio were measured to reflect the mechanical properties. The membranes were also observed with transmission electron microscopy (TEM) and atomic force microscopy (AFM) to reveal the state of dispersion and dimensions of NCC. The porous structures of dialysis membrane were researched with both scanning electron microscopy (SEM) and AFM.