Abstract: Small towns in China are the bridges of economic and cultural exchanges between cities and rural areas, and the spatial carriers of rural revitalization and urban-rural integration. However, in the rapid urbanization process, some small towns are shrinking, with such manifestations as population loss, job shortage, and backward public services. Therefore, it is of theoretical and practical significance to identify and evaluate the shrinkage of small towns. This study took the administrative towns of Jilin Province as the research object, identified the shrinkage status of small towns using the change rate of population from 2009 to 2017, and analyzed its characteristics and difference patterns. With the aid of Geodetector, this study explored the differences in the influencing factors of shrinking towns by different functional types. This study found that the shrinking towns was widespread in Jilin Province, and presented a spatial distribution pattern of 'eastern-southern shrinkage' with significant agglomeration characteristics. The shrinking towns were mainly agriculture-type, resource-type, and processing-type. Demographic structure, location conditions, and public services were the main factors affecting the shrinking towns in Jilin Province, and population agglomeration was the common factor affecting the different types of shrinking towns. The development of shrinking towns should take 'smart development' as the basic concept, improve the quality of town development, strengthen the town governance by type, and promote the transformation of town functions.