In view of the situations that the locations of high-speed rail terminals in some cities are far from the city centers, this paper put forward an approach to design feeder bus lines considering two aspects of demands. One is recent demand for transporting high-speed rail passengers between city centers and rail terminals; the other is long-term demand for directly connecting the bus system in city centers and the bus system in the emerging city unit around rail terminals. The optimization model for selecting the bus lines was built based on the two aspects of demands and then the related solution ant-colony algorithm was designed. The case of designing the feeder bus lines for anting rail terminals on Shanghai-Nanjing intercity railway was used to illustrate the model and the algorithm. The index showed the optimized feeder bus lines have the characters of quick and reliable service quality and good potential for the transition to express lines in the future.