Economic simulation systems such as computable general equilibrium modeling have been used to predict the impacts of climate change on the economy and evaluate countermeasures to mitigate its effects. In this regard, forming an assumption about international trade in agricultural products becomes problematic if limited information is available on substitution between domestic and imported agricultural products. This study examined the substitution patterns of Japanese consumers between domestically produced and imported agricultural products such as broccoli, kiwifruit, rice and apples using discrete choice experiments. Three web surveys were conducted in January 2011, February 2012 and January 2013 to gather responses to the discrete choice experiment questions for each of the four products. The responses were analyzed using the error components multinomial logit model. The results showed that the substitution of imported products for domestic sources was relatively large in the case of broccoli and kiwifruit and relatively low in the case of rice and apples. Although economic simulation systems sometimes assume that substitution patterns between domestic and imported products are fixed for different kinds of agricultural products, our results indicate that this assumption does not necessarily apply in all cases.