“The battle for sustainable development, for delivering a more environmentally stable and healthier world, is going to be largely won and lost in our cities.” Klaus Toepfer, Former Executive Director of United Nations Environment Programme said. "Over the past 50 years, humans have changed natural ecosystems more rapidly and extensively than in any comparable period in human history," said Dr LEE Jong-wook, Director-General of the World Health Organization. Approximately 60% of the benefits that the global ecosystem provides to support life on Earth (such as fresh water, clean air and a relatively stable climate) are being degraded or used unsustainably. World Health Organization published a report[1] in 2005 to warn that harmful consequences of this degradation to human health are already being felt and could grow significantly worse over the next 50 years, particularly acute to poorer countries. Harbin, a large city with almost 10 million populations in the northeast of China, is suffering serious ecological problems such as wetland degradation and biological diversity reduction. Harbin Eco-corridor System (HES), one of the core ecosystems in urban area of Harbin, is a representative serious degradation urban ecosystem in Harbin. So Harbin government is searching for a sustainable way to develop Harbin Eco-corridor System. Harbin Eco-corridor System, as an urban river ecosystem, is located along Songhua River with 123km length and 4.5km width, and consisted with 15 islands. Wetland is one of the important resources in the ecosystem. The ecosystem is not isolated with Harbin, even plays a crucial role for the progress of Harbin. It not only keeps the biological diversity in ecological aspects, but also has the value to create economic income and can keep carbon emission under control. So Harbin Eco-corridor System is expected to be sustainable from ecological, social and economic aspects. Harbin Eco-corridor Restoration and Conservation Plan and Developing Wetland Tourism are proposed strategy from Harbin government for the sustainable development in the future 30 years. But is the strategy the right way to help Harbin government to realize the objective? Policy analysis from the perspective of complex ecological-economic-social system and multi-stakeholders are expected. This paper proposes a policy analysis approach to help Harbin government to test the proposed policy. Moreover, identify the most robust policy for government through comparing the proposed one with alternatives. Additionally, find weaknesses of robust policy and propose preventive actions. The approach is consisted with eight steps. First, we can get a general description about what’s happening and what’s the problem in Harbin Eco-corridor System and what is the plan of Harbin government to solve the problem. Second, based on the problem and the proposed solution, objective analysis is conducted. The main goal-achieving a sustainable Harbin Eco-corridor System is divided into three sub-objectives: more ecological effective, more economic effective and more social effective. In order to make the sub-objectives measurable, nine indicators with units and weights are selected in criteria analysis, they are the area of wetland, wetland water consumption cost, Total CO2-equilavent of wetland, the number of employee in HES, Investment return rate, Total amount of revenue and The number of annual visiting times. The expected target value of each indicator is designed based on some documents from government. Meanwhile, because for each stakeholder, it has its own weight for each indicator, stakeholder analysis is conducted to get an integrated weight for each indicator. Third, external factors analysis is conducted to identify flooding, social power and demography as external factors which cannot be controlled by government but can bring large impact to the system in times of change. Fourth, causal relations analysis is an essential step for simulation to construct the structure of the system. Most of the causal relations are referred from research outcomes of public academic papers. Fifth, the causal relations among factors are coded by data for the establishment of a model. After verification and validation, the model is built access to reality as nearly as possible. Sixth, proposed policy and alternatives are designed. Seventh, scenario is designed. Eighth, all the alternative policies are tested in different scenarios in the model and the most robust policy comes out. Through policy analysis, a sustainable development of Harbin Eco-corridor System can be achieved through: replenishing water for wetland and developing tourism, which is recommended by this dissertation. In detail, thought sensitivity analysis and policy test, replenishing water with 176900 tons per year is a sufficient condition for the wetland to recover wetland in Harbin Eco-corridor System. While, developing tourism has some alternatives-do not developing any industry, developing eco-agriculture or developing real estate. Through comparison, we found that developing tourism is a most robust way for government to get economic and social benefit from Harbin Eco-corridor System without at the cost of ecological loss. Recommended policy effect can be predicted: in ecological aspect, replenishing 176900 tons water per year for wetland can recover most part of island area into wetland as government expected in the next thirty years. In economic aspect, total amount of revenue in tourism will reach to 354billion Yuan, and total number of annual visiting times will reach to22.75million times per year in Harbin Eco-corridor in 2040. Average investment return rate is 43%. The predicted values of economic indicators are close to target. In social aspect, the tourism industry will bring 20633 employee positions in the system every year. Total CO2-equilavent value of wetland will reduce 31% of the value in the situation that wetland structure is maintained as the current proportion. However, there are two weaknesses of the developing tourism. First, tourism investors will face with some barriers: large initial investment and long investment return period. By analysis with increasing business tax rate from 5% in 2010 to 20% in 2040, tax credit solution is tested to be one of solutions. The total water consumption cost for replenishing wetland with 15 billion RMB will be covered by the total tax with 46 billion RMB before 2030, Even if the government always keeps fixed business tax rate at 5%, the gap will be covered at around 2035. Second, developing tourism also will bring lots of garbage, if without dealing with it in time, water quality in the system will be affected. One of the solutions-controlling the number of tourist is tested by model in this paper, 1km2 opened tourism area can maximum for 867 tourists per day would be a criterion for controlling the number of tourist. In conclusion, the approach proposed by this paper is to help government to get a deep understanding of Harbin Eco-corridor System, to achieve a general consistent policy in multi-actors environment, to test whether a policy is robust, to identify the barriers in proposed policy and to provide recommendation for the sustainable development of Harbin Eco-corridor System. However, it is difficult to make sure that the model is exactly the same as reality, the variance is mainly on model structure and data collection. Future researches are listed in chapter6.4. Meanwhile, there are some limitations for the approach to be used in China. First, Leader-oriented decision style will result in the ignorance of stakeholders’ perceptions. Second, promotion-oriented decision style probably leads to the absence of continuously fiscal budget for ecological recovery in the next political term. Third, the lack of post policy assessment and accountability system maybe produce policy strategy preferred by interest group, rather sustainable policy strategy. In order to avoid the barriers, some future researches are proposed in chapter6.3.