After Liu Yu seized the Jin throne in 420 and established Liu Song, he created Xu the Duke of Nanchang and made him the governor of the capital region, Yang Province (揚州, modern Zhejiang and southern Jiangsu). He was regarded as a talented official who did not display emotions easily. The minister Zheng Xianzhi (鄭鮮之) once, while observing Xu and Fu Liang, commented, "If you hear the words that Xu and Fu spoke, you will no longer consider yourself a learned person."
