Legal studies on e-commerce transaction by normative juridical approach and by the used of primary and secondary legal material have found that firstly, law prevailing on the transaction refers basically to a choice of law agreed by parties or, secondly, if it is not, the choice of law may refer to a point-link which addresses to an extraordinary achievement of parti which trully having characteristic as Rome Convention. The Act of Information and Electronic Transaction No. 11 year 2008 stated that if parties do not make choice of law in International Electronic Transaction then the applicable law shall be referred to Private International Law. However, the e-commerce transaction is across border, the question is: whether the principles of Private International Law shall be applicable into national law system of any state without the need of harmonization to the related national law system?