In this paper, following Richardson et al., we suggested a regional economic impact model combining regional input-output model with a spatial allocation model based on a Grain-Lowry type spatial interaction model. We applied this model to the estimation of the economic impacts of Korea-US FTA on the agricultural sector and inter-industrial ripple effects in GyeongGi-D. In particular, we estimated the economic impacts for 31 sub-regions in GyeongGi-Do by 15 industrial sectors. We found that there are significant inter-industry economic effects resulting from the impacts of Korea-US FTA on the agricultural sector in GyeongGi-Do. We also found that the spatial distribution of inter-industrial impacts are quite different across regions.