Macroeconomic Model of the Nigerian Economy. The study estimates and evaluates, using the policy simulation, the relative impact of monetary and Fiscal Policies on some macroeconomic aggregates in the Nigerian economy. Another objectives were to specify and construct a structural model of the Nigerian economy which will enable us understand the workings of the economy. Specifically policy simulation enable the researcher to evaluate overtime the performance of some policy variables in the economy especially as regard to policy forecast and analysis. This provides an effective tool for sound management of the economy.