The Big Swords Society (Chinese: ; pinyin: ) or Great Knife Society was a traditional peasant self-defence group, widespread in North China during the Qing Dynasty and noted for their reckless courage. They were local groups of small-holders and tenant farmers organized to defend villages against roaming bandits, warlords, tax collectors or later the Communists and Japanese.
The Society was founded in the early 1890s by Liu Shiduan, who lived in Caozhou prefecture in southwestern Shandong. The Grand Masters of these societies claimed to make the members invulnerable to bullets by magic. Both the Big Swords and Red Spears societies had taken part in the Boxer Rebellion in North China in 1900. During the first three decades of the 20th century, many peasants emigrated to the Northeast from Shandong and Hebei provinces where the Boxers had been most influential. The peasants revived the Big Swords Society as a measure of self-defence against the depredations of bandits and warlords. Because of a large immigration to Northeast China to escape the chaos in North China, they were also active in Manchuria.
In 1927, the Fengtian government's harsh taxes and ill-treatment of local people in the Linjiang area, close to the Korean border, led to the Big Swords Society being organised there on a large scale, triggered by the collapse of the prevailing Feng-Piao paper currency. In January 1928, the Society rebelled against the Fengtian government, seizing the town of Tonghua for a short time. During the rebellion the Big Swords were respected by the peasants because they did not harm or plunder the common people, but resisted the officials of the warlord Zhang Zuolin.