Wetland plays an important role in urban ecosystem of Shanghai. However, the total area of wetland has decreased significantly over the past few decades, which has affected the supply of urban ecosystem services in Shanghai. In this study, we simulated the changes and future scenarios of wetland ecosystem services in Shanghai with a self-established system dynamics model. The results show that (1) the model is effective and practical to meet our simulation purpose. Moreover, the model parameters can be modified to simulating scenarios of wetland ecosystem service change in Shanghai under multiple policy conditions, which are useful for supporting wetland conservation and ecological planning in Shanghai; (2) four simulation scenarios based on different "growth rate of wetland area" can indicate wetland ecosystem services of Shanghai with different rates of economy development. For all the simulation scenarios, cultural service value of wetland accounts for the largest percentage (64%) and an increasing trend during the study period can be observed, followed by the regulating service value with an increasing trend as well. Among all of the ecosystem service values, supply service value is the smallest, and it is with a downward trend; (3) in 2025, with the current policy, the wetland area of Shanghai will decrease to 37.92×10⁴ hm². The total value of wetland ecosystem services will be 4711.56×10⁸ yuan, which accounts for 20% GDP of Shanghai, i.e., 1.95×10⁴ yuan per capita.