A temperature- and pH-dependent hydrogel was studied with interpenetrating polymer network (IPN) hydrogels constructed with water-insoluble chitosan and polyallylamine. Various IPNs were prepared from different weight ratios of chitosan-polyallylamine. Crosslinked-IPN hydrogels exhibited relatively high equilibrium water content (EWC) in the range 80-83%. The EWC of IPN hydrogels depended on pH and the amount of complex, which is the content of chitosan and polyallylamine. The differential scanning calorimeter (DSC) thermogram of fully swollen IPN hydrogels appeared between 3 to 4 degreesC. The IPNs exhibited two glass-transition temperatures (T(g)s), indicating the presence of phase separation in the IPNs as exhibited by dielectric analysis (DEA).