The position of the People’s Consultative Assembly of the Republic of Indonesia (MPR) as the high state institution fundamentally changed after the amendments to the 1945 Constitution. Previously the MPR was the highest governing body in Indonesia. Nowadays the position and the authority of the MPR in the Indonesian constitutional structure is no longer the highest state institution then is equal to other high state institutions. It is a consequence of the presidential system of government, where the position of all high state institutions is balanced and the principle of “checks and balances” between branches of government is implemented. This paper is a normative legal research examining the amendments to the 1945 Constitution, especially the provisions governing the authority of the MPR as contained in article 3 of the Basic Law. Despite all the changes, the MPR is still being the highest legislative branch in the Indonesian political system. This is because the MPR still has the authority to amend the Constitution.