The purpose of this study was to estimate the marginal willingness to pay (MWTP) for attributes of ecotourism in Dokdo using a choice experiment. Attributes include ecotourism courses, interpretive service by professional guide, transportation, and prices. Their levels include course A. B or C for ecotourism. Yes or no for interpretive service, ferryboat or helicopter for transportation, and six levels of prices from KRW 50.000 to 300.000. To this end both onsite and Internet surveys were conducted for residents in 16 metropolitan cities and provinces. The results of multinominal logit model show that course B and C, interpretive service, transportation, price, age, and income were statistically significant in explaining the probability of participation in Dokdo ecotourism. The results also indicate that MWTPs of changing course A to B and C were increased as KRW 78.823 and 110.62, respectively. MWTP of changing from no interpretation to interpretation was increased as KRW 60.517. MWTP of changing from ferryboat to helicopter was increased as KRW 10.667. but the former seems to be practically economical.