Marriage was a very deep and strong as a liaison between a man and a woman in the form of a family or household. Mixed marriage is a marriage between two people in Indonesia are subjected to different laws, because of differences in nationality and one party of Indonesian nationality. This marriage means there will be loss of one nationality husband or wife, son and citizenship status of children.So the elements contained in mixed marriages are marriages carried out in the jurisdiction of Indonesia and each subject to different laws because of differences in citizenship, which one of the parties must be Indonesian citizens. And the terms of mixed marriage in article 59 paragraph 2 of Law no. 1/1974, of this article denotes the principle of Lex loci actus which denotes where the legal act takes place. This means that mixed marriages in Indonesia are conducted according to Indonesian marriage law.