Yi Quan is a style of Internal Gong Fu founded by Sifu Wang Xiang Zhai, around 1925 in China. He was born in 1885 in the province of Hebei and begun his practice of martial arts in the Xing Yi Quan style during his childhood with his sifu Guo Yun Shen. From 1907, Wang Xiang Zhai began his search for knowledge and he also traveled across China, testing his Gong Fu.
When he created Yi Quan he based it in the Xing Yi Quan, Ba Qua Zhang, and Tai Ji Quan styles, using also the Qi Gong and the Chan Xue. Finally, Wang Xiang Zhai adapted the techniques from the Shaolin temple. Adding to all that, he included scientific-based training techniques.

From 1940, Wang Xiang Zhai focused his efforts in the development and popularization of the Gong Fu, frequently publishing his articles in the Beijing Shi Bao and Xin Min Wan Bao newspapers. In those articles, Wang Xiang Zhai always suggested that there should be no separation in the styles of martial arts, and that they should be studied as a single system.

The basic exercise of Yi Quan is the Zhan Zhuang, which is an apparently static posture in which one exercises tension and relaxation, training body and mind. The Yi Quan theory is based in the fact that the movements of the body constitute the contradiction between tension and relaxation, which has an influence over the psychic and physical condition. The training methodology of Yi Quan can be used in any athletic activity.