No information about Xu Shanji was found. Xu Shanshu was born and died in the early Ming Dynasty 1353- 14 19, and was born in the 23rd year of Hongwu (1390), with outstanding achievements. Wen Jian was a doctor in the spring of the first year (1399). In the second year of Yongle (1404), Hori Chunfang was knighted by the Crown Prince (later Renzong). In October of seventeen years, he died of illness. After Injong ascended the throne, he was posthumously presented to Prince Shaobao.
The book Geographical Instructions of the Son of Man written by these two people should be about 1400.