The purpose of this research is to test the interest rate, inflation rate, Dollar exchange rate, and the Straits Times Index (STI) simultaneously and partially significant influence on the Jakarta Composite Index (JCI). This study is included into explanatory research. Samples used in this study are monthly data of interest rates, inflation rates, Dollar exchange rates and STI during the period January 2010 to June 2013. The method used is multiple linear regression. The results showed that simultaneously all independent variables influance the JCI from January 2010 to June 2013. The magnitude of the effect caused by the four independent variables is equal to 71.4%, while the remaining 28.6% is likely influenced by other variables outside the model of this research. While partially, inflation rate does not affect to JCI, BI rate have negative affect to JCI, the Dollar exchange value negatively affect to stock index, and the STI has a positive effect on JCI. The most dominant variable affecting JCI is BI Rate. Based on this research, stock investors should pay attention to interest rates, inflation rates, Dollar exchange rates and STI before settling on their investment decisions, so they can make the right decisions to get maximum benefit.