The Communist Party of China issues the "May 16 Notice", marking the beginning of the Cultural Revolution.

The Cultural Revolution, formally known as the Great Proletarian Cultural Revolution, was a sociopolitical movement in China from 1966 until Mao Zedong's death in 1976, launched by Mao, the Chairman of the Chinese Communist Party (CCP) and founder of the People's Republic of China (PRC). Its stated goal was to preserve Chinese communism by purging remnants of capitalist and traditional elements from Chinese society, and to re-impose Mao Zedong Thought (known outside China as Maoism) as the dominant ideology in the PRC. The Revolution marked Mao's return to the central position of power in China after a period of less radical leadership to recover from the failures of the Great Leap Forward, which caused the Great Chinese Famine (195961). However, the Revolution failed to achieve its main goals.Launching the movement in May 1966 with the help of the Cultural Revolution Group, Mao charged that bourgeois elements had infiltrated the government and society with the aim of restoring capitalism. Mao called on young people to "bombard the headquarters", and proclaimed that "to rebel is justified". The youth responded by forming Red Guards and "rebel groups" around the country. A selection of Mao's sayings were compiled into the Little Red Book, which became a sacred text for Mao's personality cult. They held "denunciation rallies" against revisionists regularly, and grabbed power from local governments and CCP branches, eventually establishing the revolutionary committees in 1967. The committees often split into rival factions and became involved in armed fights known as 'violent struggles', to which the army had to be sent to restore order. Mao declared the Revolution over in 1969, but the Revolution's active phase would last until at least 1971, when Lin Biao, accused of a botched coup against Mao, fled and died in a plane crash. In 1972, the Gang of Four rose to power and the Cultural Revolution continued until Mao's death and the arrest of the Gang of Four in 1976.

The Cultural Revolution was characterized by violence and chaos. Death toll claims vary widely, with estimates of those perishing during the Revolution ranging from 250,000 to several million people, a number comparable to various disasters in China by death toll. Beginning with the Red August of Beijing, massacres took place nationwide, including the Guangxi Massacre, in which massive cannibalism also occurred; the Inner Mongolia incident; the Guangdong Massacre; the Yunnan Massacres; and the Hunan Massacres. Red Guards destroyed historical relics and artifacts, as well as ransacking cultural and religious sites. The 1975 Banqiao Dam failure, one of the world's greatest technological catastrophes, also occurred during the Cultural Revolution. Meanwhile, tens of millions of people were persecuted: senior officials, most notably Chinese president Liu Shaoqi, along with Deng Xiaoping, Peng Dehuai, and He Long, were purged or exiled; millions were accused of being members of the Five Black Categories, suffering public humiliation, imprisonment, torture, hard labor, seizure of property, and sometimes execution or harassment into suicide; intellectuals were considered the "Stinking Old Ninth" and were widely persecutednotable scholars and scientists such as Lao She, Fu Lei, Yao Tongbin, and Zhao Jiuzhang were killed or committed suicide. Schools and universities were closed with the college entrance exams cancelled. Over 10 million urban intellectual youths were sent to the countryside in the Down to the Countryside Movement.

In December 1978, Deng Xiaoping became the new paramount leader of China, replacing Chairman Hua Guofeng, and started the "Boluan Fanzheng" program which gradually dismantled the Maoist policies associated with the Cultural Revolution, and brought the country back to order. Deng together with his allies then began a new phase of China by initiating the historic Reforms and Opening-Up program. In 1981, the CCP declared and acknowledged that the Cultural Revolution was wrong and was "responsible for the most severe setback and the heaviest losses suffered by the people, the country, and the party since the founding of the People's Republic." In contemporary China, differing views exist about the Cultural Revolution. Some view it negatively; among some of them, it is referred to as the "ten years of chaos". However, others, particularly members of the working class, view it positively.

The Chinese Communist Party (CCP), officially the Communist Party of China (CPC), is the founding and sole ruling party of the People's Republic of China (PRC). The CCP was founded in 1921 by Chen Duxiu and Li Dazhao. Mao Zedong was a founding member of the party and rose through its ranks to become its leader and chairman in 1943. The CCP under his leadership emerged victorious in the Chinese Civil War against the Kuomintang, and in 1949 Mao proclaimed the creation of the People's Republic of China. Since then, the CCP has governed China as the leader of the United Front coalition with eight other parties, and has sole control over the People's Liberation Army (PLA). The Constitution of the Chinese Communist Party outlines the ideological beliefs of the party, collectively referred to as Socialism with Chinese characteristics, which consist of Marxism–Leninism, Mao Zedong Thought, Deng Xiaoping Theory, the Three Represents, the Scientific Outlook on Development, and Xi Jinping Thought. Each successive leader of the CCP has added their own theories and beliefs to the party's constitution. As of 2021, the CCP has more than 95 million members, making it the second largest political party by party membership in the world after the Bharatiya Janata Party based in India.In 1921, Chen Duxiu and Li Dazhao led the founding of the CCP with the help of the Far Eastern Bureau of the Communist Party of the Soviet Union and Far Eastern Secretariat of the Communist International. For the first six years of its history, the CCP aligned itself with the Kuomintang (KMT) as the organized left-wing of the larger nationalist movement. However, when the right-wing of the KMT, led by Chiang Kai-Shek, turned on the CCP and massacred tens of thousands of the party's members, the two parties split and began a prolonged civil war. During the next ten years of guerilla warfare, Mao Zedong rose to become the most influential figure in the CCP and the party established a strong base among the rural peasantry with its land reform policies. Support for the CCP continued to grow throughout the Second Sino-Japanese War, and after the Japanese surrender in 1945, the CCP emerged triumphant in the communist revolution against the KMT government. After the retreat of KMT to Taiwan the CCP established the People's Republic of China on 1 October 1949.

Mao Zedong continued to be the most influential member of the CCP until his death in 1976, although he periodically withdrew from public leadership as his health declined. Under Mao, the party completed its land reform program, launched a series of five-year plans, and eventually split with the Soviet Union. Although Mao attempted to purge the party of capitalist and reactionary elements during the Cultural Revolution, after his death these policies were only briefly continued by the Gang of Four before a less radical faction seized control. During the 1980s, Deng Xiaoping directed the CCP away from Maoist orthodoxy and towards a policy of economic liberalization. The official explanation for these reforms was that China is still in the primary stage of socialism, a developmental stage similar to the capitalist mode of production. Since the collapse of the Eastern Bloc and the dissolution of the Soviet Union in 1991, the CCP has emphasized its relations with the ruling parties of the remaining socialist states, and continues to participate in the International Meeting of Communist and Workers' Parties each year. The CCP has also established relations with several non-communist parties, including dominant nationalist parties of many developing countries in Africa, Asia and Latin America, and social democratic parties of Europe.

The Chinese Communist Party is organized on the basis of democratic centralism, a principle that entails open discussion of policy on the condition of unity among party members in upholding the agreed-upon decision. The highest body of the CCP is the National Congress, convened every fifth year. When the National Congress is not in session, the Central Committee is the highest body, but since that body usually only meets once a year, most duties and responsibilities are vested in the Politburo and its Standing Committee. Members of the latter are seen as the top leadership of the Party and the State. Today the party's leader holds the offices of general secretary (responsible for civilian party duties), Chairman of the Central Military Commission (CMC) (responsible for military affairs), and State President (a largely ceremonial position). Because of these posts, the party leader is seen as the country's paramount leader. The current leader is Xi Jinping, who was elected at the 18th National Congress held on 15 November 2012, and retained his position at the 19th National Congress held on 25 October 2017.