本文探討資本主義工業化進程、國內移民、公民權不平等三者之 間的關係。作者以公民身分差序(differential citizenship)的概念，解釋中國農民工所遭受的制度性歧視，尤其是在社會福利等面向。農民工在目前中國資本主義發展框架中，同時遭受著階級與身分的雙重剝削。中國市場經濟經過三十幾年的發展，民工已經成為藍領勞動階級中最重要的一個組成部分。民工階級是後毛時期開放人口流動以及世界生產分工結構重整的產物。民工的身分特徵，起源於毛時代的城鄉二元體制。「改革開放」時期，民工作為「外來人口」被排除在移居城市福利體制之外。近年來，由於社會經濟不平等的現象加劇，中國 中央政府採取新的政策，要求移居地政府改善民工生活工作條件，但是新形態的城市自我保護主義卻隨之興起，城鄉二元體制發生了歷史—空間的轉型，並且構成了剝削民工機制的制度性基礎。本文解釋這種新城市保護主義形成的背景與過程，而公民身分的制度化排除機制是關照的焦點。尤其在東部沿海的發達城市，地方政府表面上將民工納入了城市公民身分體制，實則藉由諸種措施而將其擺放在次等市民的制度位置，從而造成既納入又歧視的結果。「農民工問題」是中國在後社會主義階段轉向市場經濟的一個深刻難題。本文將問題導向了資本主義與公民權發展之間的比較歷史視野，並指出公民身分差序體制對於民工階級形成的重大影響。

The paper explores the interrelationships among capitalist industrialization, domestic migration, and the inequality of citizen rights. The concept of differential citizenship (gongmin shenfen chaxu) is defined and used to explain the discriminatory treatment of rural migrant workers, especially in the sphere of social welfare. Situated within the Chinese style of capitalist development, migrant laborers suffered a double exploitation in terms of economic class relation and citizen status. The migrant working class was created by a dual process of restructuring the division of labor in world production and massive population movement in the post-Mao epoch. The disadvantaged status of migrant workers originated in the rural-urban divide and the household registration (hukou) system during Mao’s time. Rural-urban dualism, retooled during post-Mao’s “open reform,” was utilized by migrant-receiving cities to exclude the “population from outside” from enjoying urban public goods. In recent years, as social and economic inequalities became aggravated, the central government adopted new policies and demanded that local governments improve migrants’ working and living conditions, but as a consequence, a new form of urban protectionism arose in response to central reform policies, and it has further institutionalized the exploitative mechanism. This paper unravels the subtle configuration of urban protectionism by focusing on the institutionalized exclusionary devices employed on migrants. Particularly, local governments of the major East-coast cities ostensibly incorporated migrants into the urban citizenship regime, but in effect relocated them into a position of inferior citizenship; a strategy of “incorporate-to-discriminate” thus emerged. The “problem of migrant workers” leads us to the issue of transitioning to a market economy in a post-socialist nation. The author adopts a comparativehistorical perspective on modern citizenship development and points out that how the differential citizenship regime has helped forge the Chinese migrant working class.