Abstract: The Chinese Area Positioning System (CAPS) is a navigation system based on communication satellites. The system can provide world-wide navigation and communication services by using iHCO (inclined Highly Circular Orbit) communication satellites, which are previous GEO (Geostationary Earth Orbit) communication satellites reset to altitudes of about 200 kilometers above the GEO for new use after their planned communication services. This paper presents a study of CAPS navigation constellations of iHCO satellites. Our study yields the most optimized CAPS navigation constellation to meet the needs of ordinary navigation-service users.