This paper examines urban China's socio-political control crisis under the impact of economic reforms as an epitome of a more general social crisis. The traditional urban institutional form of socio-political control in the People's Republic of China (PRC), the work unit form of control, is a variant of age-old forms. The latter's reproduction in variant form in the former was premised upon the fact that the PRC's industrialization was carried out by a peasant-based party creating a new working class of rural migrants engaged in non-market production and exchange. The persistence of non-market economic relations ensured this form of control's continued reproduction. Post-1978 market-oriented reforms have undermined this form. As the emergence of new forms has been slow, a socio-political control crisis has arisen, at a time when millions of urban employees are being thrown out of work. In dealing with the crisis, the official trade union, an organic constituent institution of the work unit form of control, plays a prominent part, in being given the tasks of sustaining this decaying form, and preventing and defusing potential social explosion. Yet, the very economic reform programme that has undermined the work unit form of control, is also gravely weakening the union.