The ultra petita decision that issued by the Constitutional Court indeed has a uniqueness that may raise the controversy in the society. Actually, the positions of ultra petita in the Constitutional Court decision are not regulated specifically in Law or Constitutional Court Regulation, so it shows that the Constitutional Court has no authority to issue the ultra petita decision. The research aims to understand and analyze further the position of ultra petita in the Constitutional Court decision. By using the normative legal research, the author found that the position of ultra petita in the Constitutional Court decision is recognized only by Justices of the Constitutional Court, but it cannot be applied absolutely in the Law of Constitutional Court Procedure especially for the Constitutional Review cases. The existence of the erga omnes and ex ae quo et bono principles in the Constitutional Court decision are the factors that make the Constitutional Court valid to issue the ultra petita decision. Although the Constitutional Court can make the ultra petita decision in the proper way, the authority of the Constitutional Court in issuing the ultra petita decision has should be limited to prevent the Constitutional Court replace the authority of the House of Representative as a positive legislator. The research suggests that the Constitutional Court should provide a restriction of authority for the Constitutional Court in issuing the ultra petita decision in form of Constitutional Court Act to keep the Constitutional Court on its authority as the negative legislator.