This paper specified an import demand function to measure the effects of trade liberalization more precisely. Using monthly data rather than annual data on import quantity, prices, and income, this study can reflect recent changes in consumer's tastes and patterns of expenditure. Under the assumption of tariff abolition, import of grape would increase to 27 thousand tons as the price fall to 1,600 won per kilogram by 2010. It has negative impacts on grape and pear producers' income. Even though considering positive effects on consumer's surplus, the loss of producer's revenue would be 5,190 million won in 2010.