The Charter of the United Nations (also known as the UN Charter) is the foundational treaty of the United Nations, an intergovernmental organization.The charter of UNO:The Charter was signed on 26 June 1945 by the representatives of 50 countries, Poland signed on 15 October 1945.There were 51 Founding Members in 1945.In accordance with Article 110, the Charter entered into force on 24 October 1945, after ratification by the five permanent members of the Security Council and a majority of the other countries.Twenty-two countries subsequently deposited their instruments of ratification.Since 1945, some of the Founding Members have changed their names, others have been dissolved and new states have succeeded them.It establishes the purposes, governing structure, and the overall framework of the UN system, including its six principal organs:the Secretariat, the General Assembly, the Security Council, the Economic and Social Council, the International Court of Justice, and the Trusteeship Council.The General Assembly formally recognized 24 October as United Nations Day in 1947 and declared it an official international holiday in 1971.With 193 parties, most countries have now ratified the Charter.?Hence, the correct answer is 51 Countries.