Ke Jiusi, a famous calligrapher in Yuan Dynasty, was a representative of the calligraphers who believe the doctrine of “back to the ancients”. His calligraphic style was deeply influenced by Zhao Mengfu, he followed the ancient rule of Jin and Tang Dynasty, also, he showed his own idiosyncrasy when taking Wang Xizhi, Wang Xianzhi and other calligraphers style as his models. In a word, Ke Jiusi’s calligraphic style fully embodies the vogue of the day in Yuan Dynasty.