Many blank spaces can still be found in the study of politics of Russian Empire in East Asia in the late 19th - early 20th centuries. One of the people who played a key role in those politics was a diplomat by the name of Georgy Antonovich Planson. Purpose of this paper is a reconstruction of his biography. Research is made on the basis of archival materials of the Central State Historical Archive of St. Petersburg and the State Archive of the Russian Federation, in particular personal diaries of Planson. The paper also describes some episodes that happened during his diplomatic service and provides insights into his travel notes. In-depth analysis of such materials helps to understand life of Russian diplomats who served in the region at the time, and thereby sheds the light on foreign policy of the Russian Empire in East Asia, for example, in Manchuria, China and Korea. Lastly, it was found out that Planson actively carried out not only diplomatic work, but also collected culturological material in his diary notes that can be used in contemporary research. Some of the cited archival materials are published for the first time.