Huaisu (625- 698), born in Nanyang City of Henan Province, was the founder of Vinaya Dongta School.

Huaisu was a Buddhist since his childhood and decided to become a monk despite his parents' opposition. In 645 of the Tang Dynasty (618-907), Huaisu apprenticed to Xuanzang, who had just returned from India, to study Buddhism. Huaisu had a Buddhist talent and studied extensively. At the age of 22, he was initiated into monkhood and started the study of Vinaya.

With the development of his knowledge on Vinaya, Huaisu found faults in the works of famous Buddhists and were unsatisfied with them. He summarized former Vinaya and wrote a new book Si Fen L¨¹ Kai Zong Ji (records on initiation of Four-Category Vinaya). From then on, Huaisu began to spread his own Vinaya opinions.

Huaisu's theory of Vinaya broke the hackneyed Vinaya and showed his originality. His claim stirred the study atmosphere at that time. Later, Huaisu's theory was named as Dongta School since he lived at Dongta Yuan of Xitaiyuan Temple. Nanshan School, Xiangbu School and Dongta School were formed as three main Vinaya schools. Afterwards, the Xiangbu School and the Dongta School gradually declined. Only the Nanshan School prospered without interruption and so-called Vinaya refers to the Nanshan School today.

Huaisu was not only a celebrated Buddhist but also a noted calligrapher whose cursive script was announced an important branch of Chinese calligraphy. His cursive script was similar in spirit to his free and unrestrained personality and influenced many people including Mao Zedong, the initial chairman of the PRC.