Abstract: The central government plays a decisive role in promoting China's economic transformation and agricultural land system changes. By constructing a multi-task principal-agent model between the central and local governments in the reform of the agricultural land system, this paper analyzes the relationship between the central government and the local governments and the factors influencing the optimal contract form and the optimal incentive contract design, then itexplores the impact of the implementationcost of the agricultural land system reform on theweight coefficients of local performance evaluation systems. The findings show that there is a positive correlation between the evaluation index of the farmland system in the optimal incentive contract and the implementation cost of the reform of the farmland system. The subjective behavior of the central government and its relationship with the local governments have largely shaped the changing path of the farmland system. Therefore, to achieve a substantial breakthrough in the farmland transfer right system, the central government's subjective intention needs to be truly transformed from“efficiency first, taking fairnessinto account”to“promoting efficiency with fairness”. Anincentive compatibility mechanism that both the central and local governments can win should be constructed, including a reformtarget-coupled local government performance appraisal system and a clear and effective land supervision system, so as to better promote the implementation of the policies.

Key words: change of the farmland systems, mechanism design theory, incentive compatibility constraint, central government intentionality