In Indonesia, money supply (M1) is related to the economic dynamics in either monetary market or goods market. This research about money supply (M1) in Indonesia aims at analyzing factors which influence money supply and to what extent the economic factors influence the money supply in Indonesia. The analysis method used in this research is Vector Autoregressive (VAR) with some variables such as money supply (M1), interest rate, Gross Domestic Product (GDP) from the 1st quarter of 2001 until 1st quarter of 2013. The data collecting method is in the form of data compilation from credible sources such as Bank of Indonesia (BI), Central Bureau of Statistic (CBS), and International Financial Statistic (IFS). To obtain adequate analysis result, several tests are taken such as unit root test, Granger causality test, andoptimal lag. VAR analysis formulates the correlation among independent variables so it also sees the analysis of impulse response and matrix decomposition. The result of analysis shows that monetary policy is effective enough to influence the increase of economic growth when the condition is under employment as seen by the monetarists. The second period explains the fact about the contribution of national income (DPDB), in which the contribution of national income (DPDB) is 6.82 %, national income (DPDB) is 92.75 %, and interest rate (DR) is 0.4 %.