The aim of this paper is to recognize the effective elements on the level of companies’ investment. So, under the effect of 7 selected variables like cash flow, Tobin ratio, growth rate of income, divided payments, announced payments, liabilities changes and paid-in capital, the level of companies' investment is to be researched. By using the data of 100 companies as a sample and applying Regression OLS from 2002 to 2008, we will continue the research. The results represent that factors like cash flow, Tobin q ratio, dividened payments, announcements and liabilities changes affect the investment level. But, the growth rate and paid-in capital have no effect on the level of investment.