Yau Kung Moon (also Yau Kung Mun and YKM)(Chinese) is a Southern Chinese martial art that originated in the Tang Dynasty (618-907 AD) with a Shaolin monk named Ding Yang (~800 AD) and is closely related to Bak Mei.

The name  is Cantonese and roughly translates to "the style of flexible power". The Hong Kong and US schools usually use the romanization "Yau Kung Moon" or "Yau Kung Mon", whereas the Australian schools use the romanization "Yau Kung Mun".

Origins

For much of its history, this style was taught only within the confines of the Shaolin Temple and then only to confirmed monks. During the time of the Qing Dynasty (1644-1911 AD) the temple was again destroyed and many of the monks were hunted and killed. One of the surviving monks was Doe Sung – a skilled Yau Kung Moon disciple. Doe Sung then taught a Buddhist monk named Tit Yun. Tit Yun was the first to pass the tradition on to a layperson when he accepted Ha Hon Hung (1892-1962) as a disciple in 1915. Ha Hon Hung had also studied Choy Lee Fut with his brother, Ha Sang and Bak Mei with Cheung Lai Chun.

In 1924, Ha Hon Hung opened up the first Yau Kung Moon Academy at the Pearl River Martial Arts Club in Guangzhou (Canton) and formed the Ha Hon Hung Sports Association. Yau Kung Moon primarily gained popularity in the Cantonese-speaking region of China, but remains somewhat uncommon outside of the region. It is taught in several countries but is most active in Guangzhou, Hong Kong, the US and Australia. 

Stylistic Distinctions

The Yau Kung Moon System is representative of southern styles in being based on a low, stable horse stance. It employs many upperbody techniques and most kicks are kept low. The YKM stance resembles the familiar "ding gee ma" or Kung-Fu side horse but back arch is more pronounced and the shoulders are thrown forward with arms and hands protecting the chest and groin area. Defense is natural since the critical areas of the body are behind the protective wall of the shoulders and arms. Kicks or punches delivered within range of the practitioner would still be out of range of vital areas. This same stance also lends itself readily to offense as the arms are already in the attack position and the back legs has the distance of leverage required for powerful kicking.

Yau Kung Moon has both an external and internal training. However, like most other styles of Kung-Fu reknowned for their internal power, the individual systems' manifestation of internal power are still, somewhat secretive. The majority of early forms are primarily external while the most advanced forms evolve into primarily internal. The external training consists of 13 fist and 28 weapon sets. Besides the 18 classical weapons (see the Eighteen Arms of Wushu), weapon sets using common farm implements (the hoe, long chair, spade, etc.) are also part of the system.