Regarding various styles of Chinese calligraphy, the cursive styles are more complicated than the standard style, seal style and clerical style in terms of stroke, structure, composition, and density of ink, and are more magnificent in the visual effect. Sung Dynasty was the golden age in the development of Chinese art and literature; the achievements in poetry and painting reached the peak. Many calligraphers appeared, especially after the Ching-Li period of Emperor Jen-Tsung. The renowned calligraphers, Tsai Hsiang, Su Shih, Huang Ting-Chien, and Mi Fei, were called “Four Masterts of Sung Dynasty.” With great contributions and influences on the art of calligraphy, they were not only representative calligraphers of Sung Dynasty, but also important masters in the history of Chinese calligraphy. The Four Masters of Sung Dynasty were also men of letters good at poetry and painting. Moreover, the Four Masters of Sung Dynasty enjoyed studying Buddhistic books or made friends with senior Buddhistic nuns. And this had an indirect influence on the four masters who naturally blended the religious thoughts into their calligraphic masterpieces. In addition to the preface and conclusion, this article includes three pars –cursive styles before Northern Sung Dynasty, popularity of cursive stles in Sung Dynasty and the reasons for it, research and analysis on the beauty of cursive styles of Four Masters of Sung Dynasty – in order to make a further investigation on the characteristics of running and cursive styles of Four Masters of Sung Dynasty and to take a look at the artistic beauty and charm of the aforesaid calligraphic styles in Sung Dynasty.