This paper treats the letters which Cambodian court exchanged with the Edo-Shogunate in the early 17th century. Copies of six letters in Khmer and twelve letters in Chinese from Cambodia, and fourteen letters in Chinese from Japan, including the replies to the former, are contained in the compilations of diplomatic documents named“Gaikoku-Kankei-Shokan 外国関係書簡,” “Gaiban-Shokan 外蕃書翰” and “Gaiban-Tsusho 外蕃通書,” which were edited by Kondo Juzo 近藤重蔵 by the beginning of the 19th century, and in “Tsuko-Ichiran 通航一覧” which were edited by order of the Shogunate around 1853. Among the thirty-two letters, five in Khmer and twenty-three in Chinese are of the early 17th century, and the others are of the early 18th century. Unfortunately, the locations of their originals are unidentified. The Chinese letters are thought to have been hand-copied with considerable accuracy, but as for Khmer, the characters are corrupted remarkably and hard to make out. The only exception is a letter of 1742, written in beautiful Aksor Mul (round characters of Khmer) which Kondo Juzo sedulously hand-copied by himself from the original which a family of To-Tsuji 唐通事 (interpreter of Chinese language) had reserved in Nagasaki.
In the Khmer letters, Cambodia is called Krong Kamvuchéa Thipadei and Japan is called Ñipon Kakacho (possibly Koku-Shu 国主). Expressions as Preah Reach Sar Pi Ñipon (royal letter from Japan) suggest that Cambodian court recognized Japanese Shogunate as something similar to the kingship of Cambodia. They assume an attitude of Metrei (friendship) between kings on even ground, in contrast to the Chinese letters which adopt humble expressions. The authors of the Khmer letters might be experts called Smien (clerk), because some marks of handsome script of Aksor Mul are recognized among deformed characters of the reproductions. As for the Chinese letters, probably some Chinese merchants were the authors and significant differences are recognized in the skill of rhetoric. Their contents are gratitude for presents, order of commodities, request of the limitation of the number of commercial ships, complaints about Japanese who committed robbery around Cambodia, and so on. The notable thing is that Cambodian court regarded the Chinese and Japanese merchants who carried the letters as their subjects, and required Japan to let them return to Cambodia as soon as the mission would be finished.