Mi Fu's "Hui Gan Tie", eighth of the nine written slips, paper, cursive script, 22.7 cm in length and 33.2 cm in width, collected by the National Palace Museum in Taipei, China.

Mi Fu studied calligraphy the most, and his greatest achievement was running script. His paintings have not been handed down to the world, but many of his calligraphy works have survived. Among the famous calligraphies after the Song Dynasty, most of them were engraved with his calligraphy. They were widely circulated and had a profound influence. Among the "four major calligraphers of the Northern Song Dynasty", they are second to none. Kang Youwei said: "The structure of Tang language is more important than the interest of Song Dynasty." This means that the calligraphers of the Song Dynasty emphasized interest and individuality, and Mi Fu was an outstanding representative of the four great calligraphers of the Northern Song Dynasty.

The Jin rhyme or Jin personality in Mi Fu's calligraphy originates from his view of calligraphy with "interest" as the core. His "interesting" thoughts on calligraphy can be found in his "History of Calligraphy", "History of Haiyue", "History of Painting", "Collection of Baojin Yingguang", "Records of Baozhang's Visits" and the inscriptions and postscripts of his letters. His representative book on calligraphy, "Hai Yue's Quotes", is an incisive discussion of his theory of "interest": learning books must be interesting, and forgetting all the good ones will lead to the mastery. Don't linger on it for a good reason, otherwise it won't work.

Mi Yuanzhang's view of "interest" is consistent with his unique "crazy" personality. The transcendent personality he pursues is exactly an "excellent" artistic outlook.