The earliest running script in the world generally refers to Preface to Lanting Collection. It is the preface to Essays by Wang Xizhi, a calligrapher in the Eastern Jin Dynasty. It is a preface written by 41 military and political officials, including Wang Xizhi, Xie An and Sun Chuo, in Lanting (now Shaoxing, Zhejiang) on March 3rd, the ninth year of Mu Tianzi in the Eastern Jin Dynasty. His calligraphy is of high artistic value, and it is called the three major calligraphy posts together with My Nephew Ji Ming's Manuscript and Cold Food Post.