The CPSU (Communist Party of the Soviet Union) arose from the Bolshevik wing of the Russian Social Democratic Workers Party. The Communist Party arose in opposition to both capitalism and the socialist of the Second International who had supported their capitals governments during war World war I.
By the other hand the CCP (Chinese Communist Party) is the founding and ruling political party of modern china boasting nearly ninety millions members.
The attitude of the CPSU to CCP during civil war after world war II that hey talks about union of both sides.