We have designed a new material with stable cholesteric structure by blending a cellulose derivative, (acetoxypropyl) cellulose (APC), with a thermoplastic polymer, poly (viny acetate) (PVAc). In the material obtained from THF solution, the compatibility between APC and PVAc was confirmed by differential scanning calorimetry (DSC) and infrared spectroscopy (IR). The materials showed colors arising from the selective reflection of circular polarized light. The colors depended on the composition of the materials. The material obtained from acetone solution showed phase separation into an APC rich phase and a PVAc rich phase, respectively. This indicated that the aggregation structure of APC/PVAc blends was affected by the preparation condition for materials. The FT IR results supported that the molecular aggregation structure was controlled by the hydrogen bonds between APC and PVAc polymer chains.