With the continuous development of human society, population increase, resource consumption and environmental pollution are increasing day by day, and the environment and resources on which tourism depends for development are more and more seriously damaged, which seriously affects the sustainable development of tourism, especially in underdeveloped areas. Hulunbuir Grassland Ecological Function Zone is the national ecological function area in China; and it is also an important ecological security barrier in northern China. Methods of raising more funding to support the ecological conservation of the Hulunbuir grasslands, while also supporting the tourism sustainability, is an important problem. In this study, the Contingent Valuation Method (CVM) was used to explore the feasibility of collecting conservation fees from tourists in grassland tourism destinations in China, determine the reasonable amount of conservation fees and the factors influencing the amount of conservation fees by face-to-face questionnaire survey. The respondents of this study is tourists who had completed their travel and were about to leave Hulunbuir, and 567 valid questionnaires were collected. The results show that: (1) tourists have the potential to create environmental resources conservation funds, and it is feasible to raise conservation funds with tourists as the main source of payments; (2) the Hulunbuir grassland conservation fee should be set at 49 yuan, which is acceptable to most tourists and will not change the number of tourists; (3) Tourists' socio-economic characteristics, travel characteristics and types of leisure activities have significant influences on the amount of conservation fees.

a b s t r a c tThis paper focuses on examining the validity and reliability of the contingent valuation method (CVM) in the case of evaluation of ecotourism resources in Dalai Lake Protected Area (DLPA). The CVM is a primary method to evaluate resource value, however, it is subject to criticism because of its bias. Many factors result in CVM evaluation bias, which decreases validity of the method. An important factor is that the CVM assumes that all of the respondents are certain about their answers. In fact, many respondents are not very certain about their answer, therefore, identifying the respondents' certainty level and exploring a proper method to address it are critical issues. There are three objectives in the present study: first, to identify the uncertainty treatment that can more significantly reduce the hypothetical bias, resulting in a greater closeness to the Willingness to Pay (WTP) in a real setting; second, to identify the determinants of the respondents' uncertainty; and third, to test the reliability of the respondents' payment in a real setting and a hypothetical setting by comparison with our study in 2010. One thousand three hundred fifty questionnaires about the DLPA were distributed in face-to-face interviews targeted at Hulunbeier inhabitants, and 1142 questionnaires were collected. The primary main conclusions are summarized as follows. First, the treatment of a real setting reduced the hypothetical bias, increased the WTP accuracy and had better reliability compared with the hypothetical setting. Second, income, impact (the impact of resource development on DLPA) and environmental attitudes had a significant positive influence on the respondents' certainty in hypothetical and real settings, and income and impact of resource development on DLPA had more significant influences in the real setting than in the hypothetical setting. Third, the computation of the mean WTP showed that the exposure model and the asymmetric uncertainty model YES6 fell within the 95% interval around the point estimated from the real model. The WTP of the SUM (symmetric uncertainty model) was much higher than that of the real model and the hypothetical model.