This research analyzes Indonesian Economy with simultaneous equation approach. In order to analyze the Indonesian Economy, this research uses consumption equation and investment equation as the structural equation and insert national income equation as the identitiy equation. These variable are used due to its largest proportion in national income that reflects the Indonesian Economy. This research was estimated using Two Stage Least Square (TSLS) method and processed by Electronic Views (E-Views). The data that used by this research is a secondary data of Indonesian Economy start from1985-2017. The result shows that there is a simultaneous relationship between consumption and investment. The variables that significally affect consumption are national income variable, consumption of previous periods, and inflation. While the variables that has significant effect on investment is national income.