To control the dynamics of dialysis-induced anisotropic gel formation, we have derived a theoretical expression for the development of the gel layer for a simple case where no cross-link sites for cross-linking agents exists and the inflow and the outflow of low molecular weight components through the dialysis membrane modify the state of polymer molecules to meet the gelation condition A series of experiments using chitosan solution were done as a model case. The experimental results were compared with asymptotic expressions of the time development equation predicted by theory, and the compatibility of the theoretical picture was examined.