Shi Xiu (石秀) was a character in the Water Margin.
Shi Xiu's ancestors were from Jinling Jiankangfu. He and his uncle made their living by travelling around and trading. Unfortunately, Shi's uncle died, and Shi Xiu made a great loss. He had no money to travel home, so he wandered around in Jizhou, selling firewood for a living. Since young, Shi Xiu had been trained in martial arts, and was a brave and straightforward man who helped those in need, thus he was nicknamed the 'Daredevil Third Brother (拼命三郎)'.
Despite Shi Xiu's nickname and his humble nature, he was extremely acute and intelligent. During the Zhu family invasion, Shi Xiu successfully escaped capture by befriending an old man, whom he rescued after the battle. He was much more capable than merely a 拼命三郎.
Once, Shi Xiu came across a group of hooligans, who were beating up Yang Xiong. He immediately went to Yang's aid and managed to chase off the hooligans. Yang thanked Shi for his help and the two felt a special affection towards each other, so they became sworn brothers. Yang brought Shi home with him and allowed Shi to work as a butcher in his stall.
Shi Xiu discovered that Yang Xiong's wife had committed adultery with a monk and went to inform him. Yang Xiong, however, believed his wife and accused Shi Xiu of molesting his wife. Yang drove Shi Xiu away in a fit of anger. Shi Xiu was unhappy and killed Pei Ruhai, the adulterer. He showed Yang the evidence and Yang brought his wife to Cuiping Mountain, where he questioned her. Yang discovered the truth and realised he had wronged Shi Xiu, so he killed his wife and the two sworn brothers left for Liangshan.
Shi Qian, who had been watching the scene secretly, appeared and wanted to join the duo on their journey to Liangshan. The trio passed by the Zhu Family Village along the way, where Shi Qian stole a chicken and was caught by the Zhus. Yang Xiong and Shi Xiu fled to Liangshan for help. Song Jiang led the Liangshan forces on their assault on the Zhu Family Village, but was defeated. Then, he managed to secure help from Sun Li, who acted as a conspirator from within the Zhu Family Village. In order to prove his loyalty to the Zhus, Sun Li captured Shi Xiu. Later, Sun Li and the Liangshan forces conquered the Zhu Family Village.
Shi Xiu became one of the leaders of the Liangshan infantry and one of the 36 Heavenly Chieftains. After Song Jiang had obtained amnesty from the government, Shi followed the heroes on their campaigns against the Liao Tartars and southern rebels. During the Fang La campaign, Shi Xiu was killed in an ambush at Yuling Pass by Pang Wanchun's archers.