Abstract: First of all ,this paper studies the definition and the concept of small city /town based on a study of many different classification criteria .Second ,this paper analyzes the key characteristics of small cities and towns ,including so-cioeconomic status ,land-use density / distribution ,residential travel and transit demand and supply .Then ,a set of indi-ces are developed to quantify the characteristics of the transportation systems of the small cities and towns ,which then are compared with those for big and middle-size cities .This helps further clarify the concept of small cities /towns and the fea-tures of transportation systems of them are identified .At last ,considering the transit development in small cites and towns ,a set of recommended indicators for optimizing transit network planning process are provided .