San Soo (San Shou) meaning "Free Fighting" is arguably one of the oldest of Chinese fighting systems still being practiced today. Dating back some 4,000 years, it is said that the Kuan Yin monks in the Guang Dong Province of Southern China did not invent the San Soo system, but innovated much of it's teachings, recorded it's evolution, and organized San Soo into four major categories of fighting; Ti - Kicking, Da - striking, Shuai - wrestling, and Na - Qin na. Even with fighting categories and physical techniques, San Soo is generally treated as a concept and not a definable art.

San Soo's method is offensive, opting to neutralize the opponent the instant that the opponent initiates aggressive behavior, rather than using defensive blocking to stop an attack. This is evident in the training of simultaneous evasion and striking, reading body language, attacking initial aggression, and attacking the attack.

San Soo's style of fighting is based upon scientific principles of physics and leverage dealing with predictable reactions and responses to certain stimuli. It is believed by the San Soo disciple that when a human body is struck in a specific area, it reacts is a predictable manner. That reaction would then expose other, more vulnerable targets. A large part of San Soo is the Shuai set.

Called Shuai Jiao, it's characteristics are extremely fast "downing" and throwing techniques used to quickly disable to the opponent. The major difference between Shuai Jiao and other wresting styles is that it emphasizes more speed in the throw. Shuai Jiao also incorporates kicks, punches and other strikes, and the shuai jiao disciples are taught to avoid falling to the ground and grappling for the simple fact that there may be multiple opponents present. Offensive, speed emphasized, aggressive, and efficient, San Soo has established it's claim as one of the oldest and efficient methods of fighting.