Abstract: The rural social governance of the underdeveloped areas faces twin problems of "poverty alleviation" and " harmony", which is mainly resulted from the restriction of the individual economy-based organization of China's rural economy. Relying on the market economy, the new collective economy has realized the double effects including the enhancement of the farmers' market capacity and the aggregation of the collective strength, through the combination of individual laborers and their capital. The experience of Wang Jiabian in Shaanxi and the model of Tangyue in Guizhou have proved that the new collective economy plays a prominent role in realizing the governance in various aspects, which include common prosperity, improvement of the rural governance and community construction, strengthening of the leadership of rural party organizations, ruralization of socialist core values, etc. The vivid practice of the new collective economy supporting rural social governance is not only the inheritance and development of Marxist's thoughts of agricultural cooperation, but also a new exploration of rural party organizations through connecting the market economy with socialist principles. It has been an important experience of rural social governance in under-developed areas for a new era.