Mao suit

The modern Chinese tunic suit is a style of male attire originally known in China as the Zhongshan suit () after the republican leader Sun Yat-sen (Sun Zhongshan). Sun Yat-sen introduced the style shortly after the founding of the Republic of China (1912–1949) as a form of national dress with distinct political overtones. The four pockets are said to represent the Four Virtues of propriety, justice, honesty, and shame; and the five buttons the branches of China's government (Executive, Legislative, Judicial, Examination, Control). 
After the Communist victory in the Chinese Civil War and the establishment of the People's Republic in 1949, such suits came to be worn widely by male citizens and government leaders as a symbol of proletarian unity and an Eastern counterpart to the Western business suit. The name "Mao suit" comes from Chinese Communist leader Mao Zedong's fondness for the style, so that the garment became closely associated with him and with Chinese Communism. Mao's cut of the suit was influenced by the Stalin tunic then prevalent among Soviet officials. Although it declined in use among the general public in the 1980s and 1990s due to the increasing prominence of the business suit, it is still commonly worn by Chinese leaders during important state ceremonies and functions.
In the 1960s and 1970s the Mao suit became fashionable among European, Australian, and New Zealand socialists and intellectuals. It was sometimes worn over a turtleneck.
Origins.
When the Republic was founded in 1912, the style of dress worn in China was based on Manchu dress ("qipao" and "changshan"), which had been imposed by the Qing Dynasty as a form of social control. The majority-Han Chinese revolutionaries who overthrew the Qing were fueled by the failure of the Qing to defend China and a lack of scientific advancement compared to Europe. Even before the founding of the Republic, older forms of Chinese dress were becoming unpopular among the elite and led to the development of Chinese dress which combined the changshan and the European hat to form a new dress. The Zhongshan suit is a similar development that combined European and Chinese fashions.
Historical development.
The Mao suit remained the standard formal dress for the first and second generations of PRC leaders such as Deng Xiaoping. During the 1990s, it began to be worn with decreasing frequency by leaders of General Secretary Jiang Zemin's generation as more and more Chinese politicians began wearing traditional European-style suits with neckties. Jiang wore it only on special occasions, such as to state dinners. Hu Jintao still wore the Mao suit, but only on special occasions, such as the ceremony marking the 60th anniversary of the People's Republic in 2009. Hu Jintao even showed up to a black tie state dinner in the United States wearing a business suit, attracting some criticism for being underdressed at a formal occasion. In the Xi Jinping administration, however, the Mao suit made a comeback as a diplomatic uniform and evening dress. 
Symbol of national sovereignty.
The Mao suit is worn at the most formal ceremonies as a symbol of national sovereignty. China's paramount leaders always wear Mao suits for military parades in Beijing, even though other Politburo Standing Committee members and other Politburo officials wear European business suits. It is customary for Chinese leaders to wear Mao suits when attending state dinners. In this situation, the Mao suit serves as a form of evening dress, equivalent to a military uniform for a monarch, or a tuxedo for a paramount leader.
The Mao suit also serves as a diplomatic uniform. Although Chinese ambassadors usually wear European business suits, many Chinese ambassadors choose to wear a Mao suit when they present their credentials to the head of state. The presentation ceremony is symbolic of the diplomatic recognition that exists between the two countries, so it carries a higher level of formality than other diplomatic meetings.