First, economics should be different types. Next, the mathematical economics is discussed. Third, we investigate the nonlinear economics, which includes the chaos economics. Fourth, we researched the topologic economics, which is related to corruption economics. Fifth, the economic theory of the knowledge economy era is searched. Sixth, the synergetic economics and the fractal economics are proposed. Seventh, methods of multinational enterprises are different economic systems. Many types of economics should be studied, such as the crisis economics.

Keywords: economics, mathematics, nonlinearity, chaos, knowledge economics, synergetics, fractal.