This book presents a number of important issues in contemporary Macroeconomic Theory. Using mathematical tools, some basic macroeconomic models related to wage rigidities, dynamic stability and the exercise of economic policy, expectations (static, adaptive and rational), financing of government budget deficits, (exogenous and endogenous ) economic growth and the modern theory of Real Business Cycles. In addition, the solved applications included at the end of some chapters contribute to a better understanding of the structure and operation of macroeconomic models.