On December 26, 1962, the China-Mongolian Border Treaty was signed in Beijing, China-Mongolian Border Treaty entered into force on March 25, 1963, after the mutual ratification in Ulan Bato. Main contents: The two sides determined the direction of the entire border line between the two countries; the two sides agreed that where the river is the border area, the dry river center line is the border area, where the road is the border area, the roads are shared by both sides, jointly administered and used; the two sides agreed that immediately after the treaty came into force, the China-Mongolian Joint Border Examination Committee was established, specifically calculated the entire border of the two countries, established the boundaries, and then drafted a protocol on the two