This paper describes the concept of a novel stay cable with a Carbon Fiber Reinforced Plastic (CFRP) and steel composite section. In this concept CFRP core conserves all the advantages of CFRP materials such as light weight and high strength, while steel coat provides protection for the CFRP core and ensures reliable anchorage performance. The steel coat can reduce cost and provide higher stiffness than CFRP materials in some length range. Following this concept, several configurations were proposed for the composite structure. Effects of the key design parameter of the proposed stay cables, namely the ratio of the CFRP section area to the whole section area, were examined through a parametric study using analytical solutions. By doing this, an appropriate range of the ${ ho}$ value was suggested. Factors that can affect the appropriate range of the ${ ho}$ value, including the horizontal projected length of stay cables, cable force, and pylon height (i.e., vertically projected length of stay cables), were also studied. Finally, the feasibility of the proposed stay cables was conceptually verified. It was shown that the proposed stay cables could be an excellent alternative to the pure CFRP or traditional steel stay cables.