This study presents a simple open macroeconomic model of Korea to generate forecasts, using monthly data series from 1980 to 1995.  In model specification, economic variables are assumed to be a nonstationary unit root process.  Especially, their cointegration and common trends are a priori identified to have meaningful economic relationships and error correction models are specified and estimated in structural forms.  The model specifications are tested by various methods and the adequacy of structural error correction models is compared to other approaches through out-of-sample forecast exercise.  The short-run responses and long-run adjustment processes of economic variables to outside socks are also examined by disequilibrium impulse response analysis.