中國經濟改革開放的過程中，雙軌制成為漸進式改革的重要特徵。本文嘗試從產權及交易成本的觀點出發，指出住房雙軌制對房地產市場交易的意義，以及制度併軌的動力與障礙。由於住房的交易本身即意味著附屬於住房上的各種權利的買賣，其價值會受區位、治安水準、公共設施、就業機會等變項的影響，因此住房改革顯然需要其他部門的制度改革配套才得以完成。作者認為，併軌並不意味著改革的完成，上海市真正的住房改革尚未完成。 In the process of China’s economic reform, dual-track approach becomes an institutional characteristic of incrementalism. From the theoretical views of property rights and transaction costs, the authors try to clarify the meanings of dual-track approach for housing market, and the barrier it causes in merging two different systems. The authors notice that larger group of overseas home buyers and the political pressure from entering WTO will raise the possible cost for dual-track system. Accordingly, an institutional change is necessary when the cost of the dual-track system is much more than its benefit. Since housing value is affected by many variables, such as location, criminal rate, public service and job opportunity…etc., housing reform requires institutional support from other sectors as well. As a result, the authors conclude that Shanghai’s housing reform has not accomplished yet. Canceling the dual-track system does not end up Shanghai’s housing reform.