Born in Xixiang Village (西鄉村), Guilin, Guangxi Province to a teacher father, Li Beiying (李培英) as the second eldest in a family of five boys and three girls. Li joined Tongmeng Hui in 1910. He was the general of the Seventh Army in the Northern Expedition. From 1925 to 1949, Guangxi remained under his influence.
Li participated in several set-piece battles in the Sino-Japanese War (1937-1945), including the Battle of Tai er zhuang.
In April 28 1948, Li was elected by the National Assembly as the vice-president, five days after his political opponent, Chiang Kai-shek became the president. The day after Chiang resigned on January 21, 1949 as a response to the Chinese Communist uprisings and several victories, Li became the nominal acting president. Li attempted to negotiate with the communists in Beijing. Such "pacifist attacks" increased the already-strong Li-Chiang tension. Li's intended and never implemented Seven Great Peace Policies were:
In November 1949, before the establishment of the Chiang government in Taiwan in the following month, Li moved to the New York using his chronic duodenum illness as an excuse (treated at the Hospital of Columbia University).
In January 1952, Chiang commanded Control Yuan to impeach Li in the "Li Tsung-jen's Illegal Conduct Leads to Job Lose Case" (李宗仁違法失職案), and officially relinquished Li of the position as vice-president in the March 1954 National Assembly. Li became a communist sympathizer and moved to Beijing with the support of Zhou Enlai on July 20, 1965. He died in Nanjing with a duodenum cancer at 78.
In Mainland China, Li's residence in the People's Republic of China is viewed by some Chinese communists as a defect that caused Li to "patriotically return to the embrace of his Ancestral Nation with smiles" -- something similarly in perception to Aixinjuelo Puyi's reformation.
Li was arranged to married to Li Xiuwen (李秀文) at 20 and separated eventually. The Lis had a son, Li Youlin (李幼鄰). In 1924, Li married Guo Dejie (郭德潔), who died of breast cancer soon after returning with Li to Beijing. Li and Guo had two sons: Li Zhisheng (李志聖) and Li Hangui (李漢魂). Li then remarried, to Hu Yousong (胡友松), who was 48 years younger than Li. Hu renamed to Wang Xi (王曦) after Li died and remarried.