为能给中等规模城市选择一种经济适用环保高效的轨道交通系统制式，通过分析我国的城市结构特征、轨道交通发展政策和现状，进而说明我国中等规模城市对轨道交通的需求具有中低运量系统需求大、对投资建设及运营经济性、环保性和运营效率安全要求高等特征，通过分析轮轨轻轨制式钢轮钢轨（高架B型车、C型车）、（跨座式）单轨、直线电机、胶轮导轨和中低速磁浮等系统对需求特征的适应性，并进行综合技术经济指标对比，指出跨座式单轨应成为轻轨（中运量）系统的主导模式，最后对如何促进跨座式单轨的发展提出了合理建议。

The characteristics of the cities in China and the policy and status of the development of rail transit systems in China are analyzed, which shows that the rail transit systems to be built in medium scale cities in China have such features as mediumlow transportation capacity, high cost efficiency in construction and operation, environmental friendliness, high operation efficiency and high safety. The adaptability of different rail transit systems, including “steel wheel + steel rail” rail transit system with Type B or Type C elevated train, straddle monorail system, linear motor system, “rubber wheel + guide rail” system and mediumlow velocity magnetic elevation system, to the medium scale cities in China are analyzed, and comprehensive technological and economical comparison and contrast is made among the mentioned rail transit systems. It is concluded that the straddle monorail system should be the dominant mode of rail transit systems with medium transportation capacity. Finally, recommendations are made on how to promote the development of straddle monorail system in China.