The effects of drying condition on the performance (ultrafiltration rate, diffusive solute permeability, and sieving) of hemodialysis membranes prepared from cellulose /N-methylmorpholine-N-oxide (NMMO), solution (NMMO membrane) and cellulose/cuprammonium solution (cuprammonium membrane; the referential membrane) were studied. The drying condition investigated was the glycerin concentration of the solution, which was used to substitute glycerin for the water in the membrane before the membrane was dried. A lower glycerin concentration in the solution brought about a lower reswelling degree (water content) in the dried membrane in pure water, which resulted in a drop in the performance of the as-cast membrane. The NMMO membrane had a high water content and a high membrane performance compared with the cuprammonium membrane when both the membranes were treated under the same drying condition. The differences in the performance between both membrane series is discussed on the basis of the results of the observation of the membrane morphology by scanning electron microscopy, the observation of the crystallinity of the membranes by wide-angle X-ray diffraction, and the estimation of the pore structure of the membranes. (C) 2003 Wiley Periodicals, Inc.