Electrochromism is the phenomenon displayed by the materials of reversibly changing color when the electric potential is applied. We have developed new type of electrochromic materials having the polyrotaxane structure, in which the semiconductive polymer (polythiophene) is wrapped by many macrocycles [tetracationic cyclophane, cyclobis (paraquat-p-phenylene)]. Compared with the reference polythiophene without macrocycle, the polythiophene polyrotaxane thin film has more homogeneous surface and brighter color, and shows larger color contrast and faster response in the electrochromic process. These results arise from two factors based on the polyrotaxane structure. One is the weakened molecular interactions between the polythiophene chains by the macrocycles. The other is the counter anions of the tetracationic cyclophane which provides the pathway for the migration of the counter anion between the electrolyte solution and the film in redox process. These results indicate that the encapsulation of the semiconductive polymers by the macrocycles is one of the powerful methods to enhance the functionality of the materials.