London Conference in 1921 was inaugurated in order to make some amendments on the Treaty of Sevres so that it could be put into effect and mutually applied. Although a committee as a single body consisted of both Ankara and Istanbul governments was expected to be present, Ankara Government managed to independently attend to the conference in addition to the Istanbul Government's. One of the main problematic on the topic was whether Tevfik Pasha, head of the committee of the Istanbul Government, left the ground to the committee of Ankara and cooperated with it or not. This study focuses on the details of the conference and speech undertaken by both of the committees at the meeting. It can be observed at the archival and published sources that both of the committees had cooperated with each other and were consistent with the arguments asserted at the conference. By this way, coherent attitude of both committees caused Allied Powers to be in conflict with each other and gave positive results in the cause of National Struggle.