The earliest references to Chinese martial arts are found in the Spring and Autumn Annals (5th century BCE), where a hand-to-hand combat theory, including the integration of notions of “hard” and “soft” techniques, is mentioned. A combat wrestling system called juélì or jiǎolì (角力) is mentioned in the Classic of Rites. This combat system included techniques such as strikes, throws, joint manipulation, and pressure point attacks. Jiao Di became a sport during the Qin Dynasty (221–207 BCE). The Han History Bibliographies record that, by the Former Han (206 BCE – 8 CE), there was a distinction between no-holds-barred weaponless fighting, which it calls shǒubó (手搏), for which training manuals had already been written, and sportive wrestling, then known as juélì (角力). Wrestling is also documented in the Shǐ Jì, Records of the Grand Historian, written by Sima Qian (ca. 100 BCE).
This information, and more about Kung-Fu, can be found at the following Wikipedia link; http://en.wikipedia.org/wiki/Kung_Fu