Abstract: Since the end of the 20th century, China has implemented large-scale ecological governance policies and the subsequent performance evaluation of the policy is an important issue worthy of deeper inquiry. This paper introduces transaction-cost analysis into the performance evaluation of ecological construction projects and identifies transaction cost in five parts—information search cost, contract signing cost, governance and operation cost, supervision cost and seeking compensation cost, then builds the calculating model of transaction cost. The concept and structure indicators of structure index and performance index are analyzed and the calculating model is built. It consists of weighted sum of three indicators—the proportion of endogenous transaction costs accounted for the transaction cost, farmers input accounted for the production cost, and the proportion of transaction costs accounted for the total cost. Taking Chicheng County of Hebei Province as an example, we calculate the transaction cost of four implemented ecological projects: water conservation project of Capital, returning farmland to forest policy, small watershed management project and comprehensive grazing prohibition project, then we analyze the average performance of the project and the performance change during the project execution. Transaction cost and performance calculation is of great significance, providing a new perspective for the comparison and performance evaluation of different ecological construction projects.