It entered into force on 24 October 1945 , after being ratified by the original five permanent members of the Security Council -- the Republic of China -LRB- after 1949 , located in Taiwan and was later replaced by the People 's Republic of China -RRB- , the Provisional Government of the French Republic -LRB- later replaced by the Fourth Republic and then the Fifth Republic -RRB- , the Union of Soviet Socialist Republics -LRB- later replaced by the Russian Federation -RRB- , the United Kingdom , and the United States -- and a majority of the other signatories .
The Charter of the United Nations is a treaty signed by many countries in 1945 .