Macroeconomics, as a branch of the economy and a fundamental component of economic science, studies economic activity as a whole at national level. The book Macroeconomics aims to theoretically ground the main concepts, theories, processes of this field of study, as well as to explain the main macroeconomic indicators. The issues discussed include: the analysis of the circular flow of income within the national economy with the notions and relationships on which it is based, the analysis of the relationship between consumption, savings, income and investments at the individual and society level, aggregate demand and aggregate supply, macroeconomic equilibrium and ways to correct imbalances that occur. The paper also analyzes specific markets at national level, such as the labour market and the monetary market, as well as the imbalances that are appear: unemployment and inflation. Economic activity in any economy of the world does not have a linear evolution, in this context the cyclical fluctuations of economic activity being analyzed. Regardless of the economic cycle that a country passes, in contemporary societies, a national economy can not be independently analyzed by the rest of the world, because effects are permanently transmitted between states as a result of the globalization of economic activity or of the creation of regional unions, such as the case of the European Union.