This technical report examines the approach toward enhancing the quality of urbanization in counties and county-level cities of the People’s Republic of China. The report focuses on fostering sustainability and inclusivity through the urban development cooperation mechanisms of the Greater Mekong Subregion Program. It reviews both national and county urbanization trends and analyzes these trends in Guangxi Zhuang Autonomous Region and Yunnan Province. It provides policy recommendations and demonstrates how these can be practically applied to support the urbanization of counties and enhance cross-border cooperation.