本文在张五常先生的由产权、交易费用、风险规避三要素构筑的佃农理论的基础上 ,加入了激励要素从而构成新的合约理论 ,接着又循着德姆塞茨的现代企业制度的三次法律修正的逻辑 ,创新性地提出第四次法律修正 ,然后 ,作者以上述理论框架为工具 ,系统地剖析了国企改革中合约安排的演进的内在逻辑 ,最后指出了国企进一步改革的方向 :实行以经理人员股权激励和员工有效持股计划为核心的股份公司制度。 Based on the theory of tenant-peasants constructed by Zhang Wuchang's three elements of property rights, transaction costs and risk aversion, this article adds the incentive elements to form a new contract theory and then follows the three laws of Demsetz's modern enterprise system Then, the author systematically analyzes the inherent logic of the evolution of contractual arrangements in the reform of state-owned enterprises, and finally points out the direction for the further reform of state-owned enterprises: Manager equity incentive and employee effective ownership plan as the core of the joint-stock company system.