Cai Yong’s contribution to calligraphy requires two things: 1. Original Feibai calligraphy. It is said that Cai Yong once passed by Hongdu Gate and saw workers painting the wall with brooms. He was inspired by the traces of whiteness on the painted walls. When he returned home, he created Feibai Book based on the inspiration he got. This kind of writing effect that emphasizes the flying white and dry brush was very popular in the Wei and Jin Dynasties. Wang Xizhi and Wang Xianzhi were both keen on this kind of calligraphy. Zhang Huaiguan, a calligraphy theorist of the Tang Dynasty, commented in his "Book Break" that "the flying white is wonderful and unparalleled, and the combination of movement and movement is magical." 2. Presided over the writing of "Xiping Stone Classic". During the Xiping reign of Emperor Ling of the Han Dynasty, Cai Yong presided over the writing of the famous official script work "Xiping Stone Classic" and made important contributions to the development and inheritance of official script later. "Xiping Stone Sutra" is one foot high and four feet wide. It stands outside the Imperial College Gate. It took eight years to complete.