Abstract: This thesis is to introduce the preparation of the chitosan-carboxymethyl cellulose (CS-CMC) hydrogel, which can occur the pHase transformation under pHysiological conditions. Firstly, the substitution degree of sodium carboxymethyl cellulose was measured by pH meter titration method, and the deacetylation degree of chitosan was measured by two abrupt titration method. The viscosity average molecular weights of sodium carboxymethyl cellulose and chitosan were determined by ubbelohde viscometer. And then the interpenetrating network hydrogel of chitosan-carboxymethyl cellulose (CS-CMC) was prepared by pHysical blending technology. The fast response hydrogel was obtained after the preparation condition study. Finally the characteristics identification and performance measurement of the obtained gel were carried out, such as infrared spectroscopy, swelling ratio, transmittance, pHase transition temperature, and so on. The results show that when the pH of CS solution reaches 4.6, 1% CMC solution mixed with equal concentrations of CS solution in the volume ratio of 0.8, the solution gelled at 41 ℃, the gel time was less than 1min. This hydrogel can be kept in the liquid at room temperature or below room temperature, while when the temperature reaches body temperature, it can quickly gelled, This hydrogel is smart and can be used in medical treatment.