In a broad sense, interest rates are not limited to bank interest itself, but also to bond markets, and even to share dividends, another way of stating dividends. In fact, in the United States, the proportion of direct financing is far greater than the indirect financing, corporate bonds, debt-financed and publicly traded shares is a very important means of financing, at this time all can use the concept of interest rates for analysis. After all, with tighter regulation and tight capital, high interest rates and high limits mean high risk, but investors should also be careful not to put money in one basket. Famous British economist hicks and others argue that the above theory did not consider the factor of income, and therefore unable to determine the level of interest rates, in 1937, and puts forward the is-lm model on the basis of general equilibrium theory. It establishes a theory of interest rates and income at the same time that the four factors of savings and investment, money supply and monetary demand interact. According to this model, the interest rate decision depends on the supply of savings and investment needs, money supply, money demand, four factors, cause a change in the saving investment, money supply and demand factors will affect the level of interest rates. This theory is characterized by general equilibrium analysis.