Hsuantsang (also known as Xuanzang, Hsuanchuang and so on) traveled to the west in search of truth fourteen hundred years ago. The most difficult and dangerous journey in his pilgrimage was from Kua-chou (Anhsi) to I-chou (Hami). It depicted not only his zeal quest of truth and steadfast and persevering spirit to a greatest degree, but also cherished the memory of human through centuries thereafter. According to "Biography of Hsuantsang", we know that he traveled along with the prolong moraine called Mo-ho-yen desert (Gashun Gobi) route. This paper makes through investigation on possible situation of the route, including all watchtowers, checkpoints, beacons and so on one by one. On the basis of criticizing most historical and geographical sources, we now have better knowledge on the township of Kua-chou, Hu-lu River and the first beacon. In the text, we also clarify how on earth Hsuantsang walked alternatively through official route and moraines, where he lost in the desert several times and not tired out to dying. In addition, this text can offer as a guide for moderns taking the same route on the Silk Road.
