Globalization era makes people become mobile and moving easily. That moment makes so many foreigners in one country especially in developing and developed countries. Foreigners also have rights to get protection from the original states. The protection is given by representatives sending state in recieving state. This is important because there is a probability for foreigner is arrested because legal case. This thesis analyzed how bilateral cooperation through mandatory consular notification (MCN) agreement is good faith between countries in protecting own citizens who live abroad. MCN agreement is further step of the countries after ratified Vienna Convention 1963 on Consular Relations. Acoording to Article 36 Vienna Convention 1963, the representative of sending state has rights to communicate with its citizens in recieving state. Two countries which has established MCN agreement should notify of representative of sending state, if there is foreigner in under arrest because of legal case. The representative of sending state should able to give consular access to its citizen who is arrested. This thesis using qualitative methodology specificly in descriptive way. All data had been gathered from books, online journal, and relevant website. Based on the data analyzis, this thesis concluded bilateral cooperation through MCN agreement is good cooperation in protecting citizens who live abroad but in practical there are some things that should be fixed especially our country, Indonesia.