After returning to Taiwan from the United States, Lee Teng-hui resumed his service at the Joint Commission on Rural Reconstruction (JCRR) while also teaching at National Taiwan University. In 1972, Lee Teng-hui was given a position as a Minister without Portfolio. In 1978, he became the appointed mayor of Taipei City. In 1981, he was further promoted to the position of Taiwan Provincial Chairman and subsequently ascended to the role of Vice President in 1984.

In January 1988, President Chiang Ching¬-kuo passed away, and Lee Teng-hui succeeded him as President. Following the recent lifting of martial law, Lee Teng-hui initiated numerous democratic reforms, such as convening a National Conference in response to the Wild Lily Student Movement, abolishing the Temporary Provisions Effective During the Period of National Mobilization for Suppression of the Communist Rebellion, dissolving the “Ten Thousand Year National Assembly” whose members had been at their posts for several decades, and repealing Article 100 of the Criminal Code. After becoming Taiwan's first directly elected president in 1996, he pushed forward various constitutional amendments. Lee Teng-hui left a profound impact on Taiwan's democracy, freedom, human rights, and national development.