Changdao Island Nature Reserve is the typical nature reserve of island in China, where the rapidly developed fishing, aquaculture and tourism, unavoidable bring a lot of environmental problems, then causing severe challenges to the sustainable development of the ecosystem in Changdao Island. In this paper, a payment card contingent valuation method was used to survey and estimate the willingness to pay of the residents and tourists in 2013 for ecosystem maintenance in Changdao Island Nature Reserve, whose results were compared with those in 2008 to test the reliability of the contingent valuation method. Results show that the average maximum willingness to pay of residents and tourists are 203.77 and 257.26 RMB/a per person, respectively, and grow 7.9% and 21.7% compared with those in 2008, respectively. The similarity of the two surveys of willingness to pay is that the tends of the distributions of proportions of residents' or tourists' willingness to pay for each bid value in different years are basically the same, and the difference is that the proportions of people willing to pay increase significantly. The former is reflected in that residents' choice of each bid value is relatively concentrated, while tourists' is scattered, and the latter presents that the residents' and tourists' growth rates of the proportion of people willing to pay are 20.5% and 19.1%, respectively. Results show that the assessment of residents' and tourists' willingness to pay for preserving ecosystem of Changdao Island Nature Reserve by the contingent valuation method is reliable, and the assessment results are influenced by the economic income and consciousness of environmental protection. Therefore, the local government should strengthen the propaganda and education of the ecological and environmental protection based on economic developing.