This article aims at elucidating a characteristic of the information function about the official business traffic in Seto-Naikai (the Inland Sea) in the early modern age. And for one phase to achieve this purpose, I set "Kuda-ri" (going from Edo to Nagasaki) of Nagasaki shogun's bureaucrats as an object example and from "Mei-wa" (明和) to "Kan-sei" (寛成) years as an object time here.
This analysis, so to speak, approaches a big problem how traffic in Seto-Naikai was supported in its age.
It became clear that "zai-ban" (a bureaucrat of a feudal clan working in port) went over the fence among the feudal clans, and to have developed original activities so that he can ensure an information of Nagasaki shogun's bureaucrats. In other words, information and "chi-so" (welcoming tourists) by a feudal clan were linked closely in this sea in its age.