In 1911 Li was a divisional commander in the army and was stationed in the city of Wuhan (Hubei province), where the anti-imperialist Chinese Revolution of 1911–12 erupted among army units. The uprising, which brought a republican government to China, had been planned to occur at a later date; hence, no recognized leaders were on hand. As the only figure of stature who had not fled the area, Li was forced by his troops to become the head of the new government, despite the fact that he had no previous association with the revolutionaries. His enthusiasm for his new position increased as the success of the revolution became assured.

On the death of Yuan in June 1916, Li succeeded him as president and held office until the brief restoration of the boy emperor in July 1917. In 1922 he was prevailed upon to resume the presidency, but in June of the following year he was compelled to resign. Li was unsuccessful in his efforts to reunify the country by negotiation rather than by military force.