This paper introduces legitimacy theory to analyze legitimacy strategies and its effect on public’s attitude. Firstly, case study summaries two dimensions of legitimacy strategies. Then an experiment in a format of 2 (response time: quick and slow) multiplied by 4 (four kinds of legitimacy strategies) factorial design is employed to testify the effect of legitimacy strategies and response time. The results suggest that the interaction effect of value and action dimensions is significant and public’s attitude is influenced by legitimacy strategies. Furthermore, response time is positively related to public’s attitude and its mediating role for legitimacy strategies is significant.