De-Stalinization (Russian: десталинизация, Destalinizatsiya) refers to a process of political reform in the Soviet Union that took place after the death of long-time leader Joseph Stalin in 1953. The reforms consisted of changing or removing key institutions that helped Stalin hold power: the cult of personality that surrounded him, the Stalinist political system, and the Gulag labour-camp system, all of which had been created and dominated by him as General Secretary, among other titles, from 1922 to 1952.
Stalin was succeeded by a collective leadership after his death in March 1953, consisting of Georgi Malenkov, Premier of the Soviet Union; Lavrentiy Beria, head of the Ministry of the Interior; and Nikita Khrushchev, First Secretary of the Central Committee of the Communist Party of the Soviet Union (CPSU). These men had all been loyal Stalinists, but they also knew that the excesses of Stalinism threatened everyone, even the very top loyalists, with arbitrary execution. They thus embarked on a process of disassembling one-man rule and rehabilitating some of the persons who had met undeserved fates.
Contemporary historians regard the beginning of de-Stalinization as a significant turning point in the history of the Soviet Union. It began during the Khrushchev Thaw. However, it subsided during the Brezhnev period and remained so until mid 1980s, when it accelerated once again due to policies of perestroika and glasnost under Mikhail Gorbachev.
More information on the Wikipedia page .