Zhang Xu is called "the sage of grass" by the world because of his superb cursive achievements and artistic feelings. Among Zhang Xu's copybooks, the most famous ones are Abdominal Pain Sticker and Four Ancient Poems, which are still collected and preserved. Abdominal Pain Post is a single engraved post with no inscription. There are always six lines on it, and * * * counts as 30 words. Judging from its handwriting, it belongs to one go, and the font is coherent and elegant. The inscription said, "I have a terrible stomachache. I wonder if it is caused by cold and heat. If you want to take rhubarb decoction, both cold and heat are beneficial. How to calculate, not clinical. " As you can see, this post is like the text of Zhang Xu's self-diagnosis when he has a stomachache. At first, a few words were written fairly well, but later they became faster and crazier. You can see the creation of cursive script and arrogance. There are always four ancient poems, first of all, Yu Xin's Taoist stepping on empty words, then Xie Lingyun's ode to the prince and the old man under the rock. This post is a work of wild grass, and its wild momentum and brushwork style can be regarded as an important masterpiece in Zhang Xu's copybook.