Abstract: Calcium alginate gel has a complex network structure of macromolecules, water molecules and ions, and its moisture content is very high (about 3500% d.b.). It is very difficult to detect the drying mechanism, and determine the critical point of stiffening reaction by normal analysis methods. The electrical impedance spectroscopy has many advantages applying in practical analysis, thus the method has been attempted to monitor the continuation of calcium alginate gel drying. The measuring conditions were determined and changes of electrical impedance properties in several kinds of drying process were measured and analyzed in this study.