In the early years after its birth, New China established diplomatic relations with the USSR, other socialist countries and some friendly countries. China publicly declared that it stood on the side of socialism.
Following the establishment of Sino-Soviet diplomatic relations, an important question calling for prompt solution in Sino-Soviet relations was how to handle the 1945 Sino-Soviet Treaty of Friendship and Alliance signed by Old China and the Soviet Union so as to set forth anew the guiding principles and legal basis for the new Sino-Soviet relations in a changed situation. During his visit to the Soviet Union in the winter of 1949, Chairmen Mao Zedong suggested to Stalin that a new treaty be signed by the two countries to replace the outdated Sino-Soviet Treaty. To this the Soviet side agreed. Subsequently, Premier Zhou Enlai led a Chinese Government Delegation to the Soviet Union for the negotiations. On 14 February 1950, the two sides signed the "Sino-Soviet Treaty of Friendship, Alliance and mutual Assistance" and other agreements. The Foreign Ministers of the two countries exchanged three notes, declaring null and void the Sino-Soviet Treaty of Friendship and Alliance and the other agreements which were signed by the Soviet Government and the Kuomintang Government of China on 14 August 1945.
The "Sino-Soviet Treaty of Friendship, Alliance and Mutual Assistance" consisted of a preface and six articles and remained in force for a term of thirty years. Its main contents are as follows:
The Two Contracting Parties undertake to carry out jointly all necessary measures within their power to prevent a repetition of aggression and breach of the peace by Japan or any other State which might directly or indirectly join with Japan in acts of aggression. Should either with Japan and thus find itself in a state of war, the other Contracting Party shall immediately extend military and other assistance with all the means at its disposal.
Neither of the Contracting Parties shall enter into any alliance directed against the other Party, or participate in any coalition or in any action or measures directed against the other Party.
The two contracting Parties undertake shall consul together on all important international questions involving the common interests of the soviet Union and China, with a view to strengthening peace and universal security.
The two Contracting Parties undertake, in a spirit of friendship and cooperation and in accordance with the principles of equal rights, mutual interests, mutual respect for State sovereignty and territorial integrity, and non-intervention in the domestic affairs of other Party, to develop and strengthen the economic and cultural ties between the soviet Union and China, to render each other all possible economic assistance and to effect the necessary economic cooperation.
Under the historical circumstances of the time, the "Sino-Soviet Treaty of Friendship, Alliance and Mutual Assistance" concluded between China and the Soviet Union was of great significance in preserving the security of both sides, maintaining peace in the Far East and the world as a whole, strengthening friendship between the two peoples and promoting the cause of socialist construction of the two countries.