Li Jing was born in 571, during Sui Dynasty's predecessor state Northern Zhou. His clan was from the Chang'an region. His grandfather Li Chongyi (李崇義) served as a provincial governor during Northern Wei, and his father Li Quan (李詮) served as a commandery governor during Sui. In his youth, Li Jing was said to be handsome and ambitious, and was talented both in literary and military matters. His maternal uncle was the great Sui general Han Qinhu (韓擒虎), and it was said that Han was impressed by his talent, stating, "You are the only person that I can talk to about Sun Tzu's and Wu Qi's strategies."