Sun Lu-Tang (1861-1932) was already renowned for his proficiency at the internal martial arts of paqua zang and xing-yi quan when he began studying Wu/Hao style tai-chi chuan with Hao Wei-Chen. He went on to combine his knowledge and create his own style of tai-chi which has been described as employing paqua's stepping system, xing-yi's legs and waist movement and tai-chi's body softness.
Sun style tai-chi retains many of the characteristics of the Wu/Hao form and follows the same sequence of movements. Like the Wu/Hoa style it utilises compact movements and natural upright stances. Although the foundation form of Sun style is a slow movement set, it is typically performed at a faster pace than the slow movements in other styles.
In addition Sun style tai-chi emphasises opening and closing, stirring and expanding. It employs complex and nimble footwork with each technique containing a corresponding stepping action. This agility together with its' higher stances, smaller steps and clench-unclench fist technique are the distinctive elements of this flowing style.
The following YouTube video shows Master Faye Yip performing the Sun Taiji 98-movement form.