Wetland is a kind of important ecosystem on the earth. To better protect wetland ecosystems, Contigent Valuation Method (CVM), a worldwide popular method for evaluating the economic value of ecosystems was applied to evaluate the non-use value of Sanjiang Plain wetland. A questionnaire of payment card CVM was developed for the survey study. We sent out the questionnaires to 552 respondents, and received 513 usable responses. Data analysis reveals that the willingness to pay of Sanjiang Plain wetland is RMB 71.66 per year. The total annual non-use value of Sanjiang Plain wetlands is more than RMB 2.4638 billion per year. This value is only the wetland of the Sanjiang Plain, if extended to cover all the natural resources of the Sanjiang Plain, its value will be significantly larger. The value of the natural resources of the Sanjiang Plain is huge, and protecting the ecological environment in Sanjiang Plain will create enormous value. This study make it available to contrast the cost of environmental protect and the value of exploitation. That will help the government and decision makers to make reasonable decisions on related issues.