The calligraphy axis of Deng Nanfeng is a vertical axis, with a height of 108.4 cm and a width of 42.6 cm, which is rare in the calligraphy works of Yuan Dynasty. According to the Complete Works of China's Calligraphy, among the nearly 300 works in seven volumes compiled by 80 calligraphers in Yuan Dynasty, there are only 7 vertical works, including 2 by Yang Weizhen, 4 by Changyu and 0 by Ni Zan/kloc. It can be said that Zhang Yu and Yang Weizhen are the pioneers of China's calligraphy from Han miscellaneous, Jun, Jun to vertical axis. Among the four vertical axis works handed down from generation to generation, the brand-new Autumn Poetry Axis, which exists in the National Palace Museum in Taipei, is the earliest one. Written in his later years (i.e. 59 years old), the scale is/kloc-0 154.3cm×34.3cm. The cursive script with seven quatrains is two lines to the right, and the next paragraph reads eight particularly small running scripts at the bottom left: "Dayuan to Zhengxin Temple. Obviously, the author has not found the proper composition of the manuscript fee, which should be regarded as his attempt to write a vertical book. The following "Zi Zhongshu Poetry Axis" is written in small letters, just like the above "Deng Nanfeng Axis", and there is no signature. Obviously, Zhang Yu has not found a mature structural position in her composition.
Two of the four-axis books are less than three feet high, which is still very small compared with the Gaotang axis, which often exceeds the height after the middle of the Ming Dynasty, but this change has caused great changes in calligraphy creation and aesthetic touch. If a large number of cursive scrolls by Zhang Xu, Huai Su and Huang Tingjian have completely divorced from practicality and entered the state of pure artistic creation, then Zhang Yu's vertical axis works have further divorced from practical functions in aesthetic form, so it can be said that this vertical axis book has entered the state of pure art from creation to aesthetics. Zhang Yu's pioneering work in vertical axis calligraphy creation.
Under the tide of retro-ism, he verbally returned to Wei and Jin Dynasties, just like Zhao Mengfu, but in creative practice, he is still in the same strain as Su, Huang and Mi in the Northern Song Dynasty, and is essentially an opponent of Zhao Mengfu's calligraphy.