In this paper is consisted of two essays about the measurement of systemic risk of Korean financial market and the analysis of carbon tax policy in the macroeconomic framework. In the first research, we analyzed about financial crises in Korean financial market by $\Delta CoVaR$, the measure of systemic risk. The endogenous crises, IMF crisis and savings banks crisis are predictable while exogenous shock, the global financial crisis is not predictable by out-of-sample prediction using balance sheet items. Size is the most powerful explanatory variables and leverage ratio, maturity mismatch are significant. These findings would help to enhance the operation of Korean macroprudential policy. In the second research, we construct a macroeconomic model to discuss the effect of carbon tax policy. We build a channel of promoting clean-technology via carbon tax revenus and it is consistent with the real world case which is validated by the empirical test. We suggest that it is effective to introduce carbon tax policy to protect the environment.