Li Xiaogong was one of the few Tang generals who achieved great independent success without being associated with Emperor Gaozu's talented son Li Shimin, and he enjoyed great reputation among the soldiers. As he was put in charge of the lower Yangtze region after defeating Fu, he rebuilt the important Southern Dynasties fortress of Shitou (near Danyang), which led to accusations that he was planning treason himself. Emperor Gaozu recalled him to the capital and had him interrogated, but after insufficient evidence was shown against him, released him and made him the minister of imperial clan affairs—a high-level position that, however, had relatively little power. He later successively served as the commandant at Liang Prefecture (涼州, roughly modern Wuwei, Gansu) and prefect of Jin Prefecture (晉州, roughly modern Linfen, Shanxi). After Li Shimin became emperor in 626 (as Emperor Taizong), his title was changed to Prince of Hejian, and he was made the minister of ceremonies.