Bai Juyi began composing poetry at age five. Because of his father's death in 794 and straitened family circumstances, Bai did not take the official examinations for the bureaucracy until the late age of 28. He passed them and also did extremely well at another examination he took two years later. As a result, he was given a minor post at the palace library, as was another successful examination candidate and poet, Yuan Zhen. They shared views on the need for both literary and political reform, and their lifelong friendship became perhaps the most famous in Chinese history. In 807 Bai became a member of the prestigious Hanlin Academy in Chang'an, the capital, and he rose steadily in official life, except for his banishment in 814 to a minor post at Jiujiang, which arose from the slander of rival courtiers. He assumed the important posts of governor of Zhongzhou (818), Hangzhou (822), and, later, Suzhou. In 829 he became mayor of Luoyang, the eastern capital, but he retired from that post in 842 because of illness.

Bai was the informal leader of a group of poets who rejected the courtly style of the time and emphasized the didactic function of literature, believing that every literary work should contain a fitting moral and a well-defined social purpose. He considered his most important contributions to be his satirical and allegorical ballads and his “new yuefu,” which usually took the form of free verse based on old folk ballads. The most prolific of the Tang poets, Bai aimed for simplicity in his writing, and—like Du Fu, a great Tang poet of the preceding generation whom Bai greatly admired—he was deeply concerned with the social problems of the time; he deplored the dissolute and decadent lifestyles of corrupt officials and sympathized with the sufferings of the poor. Many of Bai's poems are quoted in the Japanese classic The Tale of Genji (Tale of Genji, The).