Li Jingsui (李景遂) (920-September 17, 958), né Xu Jingsui (徐景遂), courtesy name Tuishen (退身), formally Crown Prince Wencheng (文成太弟), was an imperial prince of the Chinese Five Dynasties and Ten Kingdoms Period state Southern Tang. He was a son of Southern Tang's founding emperor Li Bian (Emperor Liezu). During the reign of his brother Li Jing (Emperor Yuanzong), he was initially designated the heir, but, having never embraced that role, repeatedly offered to yield the position to Li Jing's son Li Hongji. Eventually, Li Jing agreed, but Li Hongji, still fearing that Li Jing would change his mind again, had Li Jingsui poisoned to death.
Xu Jingsui was born in 920, during the reign of Yang Longyan the King of Wu. His father, then known as Xu Zhigao, was serving as Wu's junior regent at the Wu capital Guangling (廣陵, in modern Yangzhou, Jiangsu), with his adoptive father (Xu Jingsui's adoptive grandfather) Xu Wen the regent taking up position at Jinling and in actual control of the Wu state. His mother was Xu Zhigao's second wife Lady Song Fujin, who was also the mother of his older brothers Xu Jingtong and Xu Jingqian and younger brother Xu Jingda. Xu Jingsui was the third son overall.
By 936, Wu's titular ruler was Yang Longyan's younger brother Yang Pu, who had taken imperial title by that point; Xu Jingsui's father Xu Zhigao was the regent, stationed at Jinling, with Xu Jingtong also there serving as his deputy. The role that Xu Zhigao formerly had during Xu Wen's regency, as junior regent at the Wu capital Guangling, was held by Xu Jingqian, who was Xu Zhigao's favorite son. However, in 936, Xu Jingqian fell ill, and was removed from the junior regency and recalled to Jinling in hopes of recuperation. Xu Jingsui, then 16, was sent to Guangling to serve as junior regent, carrying the titles of Menxia Shilang (門下侍郎) and Can Zhengshi (參政事), as a de facto chancellor. (Xu Jingqian would not recover, however, and would die in 937.)