 In 795, the Ministry of Appointments sent him to be a tutor to the Heir Apparent, a sign that he was destined from a prominent career.However, in 796, his father suddenly died and he had to return to Yangzhou.In 800, Liu became a secretary to the important scholar-official Du You who had been made the military governor of Xusihao Circuit, in charge of suppressing an insurrection in Xuzhou, enabling Liu to see army life at first hand.