This paper aims to analyze the chance of upward social mobility for rural migrants in Chinese cities by reviewing their “ownership of opportunity”. During the past three decades，the distribution of opportunity in China has been improved through institutional reform and，indeed，people from rural area have been given more chances to choose their career and lives. However，due to the lack of the ownership of opportunity caused by the unreasonably unfair policy of the Reform，they have not yet got reasonably fair opportunities for upward social mobility. In current social context that has been heavily shaped by relevant policies，people from rural area are excluded from all the main routes for upward mobility in urban society despite the fact that they have been working and living in cities for years. Consequently，their social mobility is isolated from that of the mainstream urban society and tends to be reproduced among themselves. Therefore，the author argues that the protection of the ownership of opportunity is the key for rural migrants to participate in the upward mobility in urban society and be fully integrated into urban society.