Gu Ruzhang or
Ku Yu-Cheung (; 1894–1952) was a
Chinese martial artist who disseminated the
Bak Siu Lum (Northern
Shaolin)
martial arts system across southern China in the early 20th century. Gu was known for his expertise in
Iron Palm hand conditioning among other Chinese martial art training exercises. He has become a legendary heroic figure in some Chinese martial arts communities.