The purpose of this research is to help investors in making decision how to invest in the stock market by analyzing the influences of liquidity, activity, and solvency ratio on company's profitability. Financial rations which are used in this research are Current Ration, Total Asset Turnover, and Debt to Total Asset as independent variables and Return On Assets as the dependent variable. This research is using the purposive sampling method with 17 sample of LQ45 companies which fulfilled the research criteria during the period 2011-2013 from 45 existing listed companies. This research is using the Multiple Linear Regression Analysis, Classical Assumption Test, and Hypothesis Testing. Based on Classical Assumption Test results prove that the data which are used in this research do not have any problem of normality, multicollinearity, autocorrelation, and heteroscedasticity. The results of Partial Hypothesis Testing show that Current Ratio has a significant positive influence on Return On Asset, Total Asset Turnover has a significant positive influence on Return On Asset, and Debt to Total Assets does not have any significant influence on Return On Asset. If Current Ratio increases, Return On Asset will decreases. If Total Asset Turnover increases, Return On Asset will also increases. Instead, the changes in the Debt to Total Asset has no impact on Return On Asset changes.