The objective of this study is to analyze how much economic impact is changed before and after the designation as biosphere reserve area by tourism. The subject region of this study is Hajun mud village which is the famous place to experience eco-tourism located in Gochang-gun. This region has been designated as a UNESCO biosphere reserve in 2013. In order to estimate the regional economic effects, we employ a regional input-output model which is derived by a RAS method. Using regional input-output model analysis, this study estimates direct and indirect effects of tourist’s expenditure on experience of Hajun mud village in Gochang-gun across associated industries between 2011 and 2013. Also, we tried to calculate a net increase in number of visitors in 2013 with considering the trend of tourist in this region and estimate a net regional economic effect after the designation as a biosphere reserve area by tourism. The empirical result could be summarized as follows : (1) the change of production inducement effect shows that regional outputs is approximately increased by 386 million won between 2011 and 2013, (2) regional value-added is increased by 223 million won during the same period, (3) regional employment is approximately increased by 20 according to the labor inducement effects of expanding tourist’s expenditure in biosphere reserve area. (4) social service industry has highly been benefited by increase in experience tourist after Gochang-gun was designated as the biosphere reserve area. (5) estimated net increase in number of visitors after the designation as biosphere reserve area is about 37,364 which is 93.4% of the absolute increase in number of visitors amounting 40,011 between 2011 and 2013.