This research has a purpose to analyze causality relationship between BI Rate and money supply (M1) in Indonesian. This research used time series data is monthly data period 2010-2012. The method of this research is method Cointegration test, Granger Causality test, and VAR. The results of analysis Cointegration test with VAR model, which means not a proper balance in the long run between BI Rate and M1. Granger Causality test analysis results, indicates that there is a bilateral causality relationship, are the BI Rate affect M1, and M1 affect BI Rate too