Contingent valuation method (CVM) is an important value assessment method that is widely used in ecological (environmental) economics; and it has unique advantages in the quantitative assessment of the value of natural resources. By questionnaire, the CVM reflects the value under the influence of environment, and it is a theory of strong evaluation. This method is used to analyze public weather service. Considering the uncertainty, the effectiveness assessment of public weather service is conducted by establishing dichotomy Logistic model (DLM). Using national sample survey data, we compare it with the method of traditional willingness to pay. The DLM is more objective when using in a quantitative assessment of national public weather service.