Abstract: Cryopreservation of cells and tissues (natural or engineered) usually involves complicated protocols for addition and later removal of cryoprotecting agents to avoid osmotic shock and toxicity to cells. The rate of CPA addition and removal is essential to cell survival. In this study, the feasibility of using porous membrane to control the rate of CPA transfer to cell environment is studied, A purpose designed diffusion chamber was fabricated. The effects of membrane characteristics (porosity and effective thickness), temperature, and initial concentration were experimentally studied. A simplified mathematical model was developed, which provides the basis to desire the membrane parameters based on tile experimental measurements.