ai Ji Quan (or T'ai Chi Ch'üan) is an old Chinese martial art of centuries that is inspired to the principle of the "Great Union" of the two cosmic forces Yin and Yang from which all things are originated. The movements and their applications in the fighting reflect this conception of the Universe: the practitioner uses to his own advantage the weakness of the enemy without oppose force to force, but with smooth and relaxed techniques.

Tai Ji Quan training represents also a healthy exercise, that strenghtens bones, tendons and muscles and improves blood circulation, metabolism and the neurovegetative system, as proved by several scientific studies both in Asia and the West. Traditional Chinese Medicine attributes to Tai Ji Quan the property to increase and to use at will the vital energy, called "Qi", equivalent to the Japanese "Ki".

There are many schools of TaiJi, in which the movements are performed in different way, but they are all similar in the basic features.

Koo style is spread especially in Hong Kong: it was created by Koo Yu Cheung, famous for his skillness in "Iron Palm" (Tit Sa Jeung) and for the Northern Shaolin Kung Fu (Bak Siu Lam), that he incorporated into the TaiJi Quan with wide movements of the arms and big, low stances. The extension of the shoulder and the "knife hand" (Sau Do) are the trademark of this style. The techniques are soft but containing big power, with graceful but very useful maneuvers for attack and defense.

Koo Yu Cheung transmitted his knowledge to the loved disciple Lung Chi Cheung, then the style passed on to the son of him, Lung Kai Ming. The lineage continues with Master Olive Hui.