Abstract: A quantitative and spatial explicit framework for evaluation the performance of farmland preservation policy is proposed by combining counterfactual analysis with scenario simulation approach.Counterfactual analysis provides an assessment approach,while the scenario simulation is used to simulate the counterfactual vision.Under the umbrella of CA,the policies are integrated into the land use conversion decision-making utility function,and thus are the link between policy and scenario simulation constructed.Case study not only indicates the importance of farmland preservation policies in declining the arable land loss speed,governing urban land disorderly expansion and optimizing spatial distributions,but also shows the competent of the proposed model for assessing the performance of China's farmland preservation policies.