ENIt is difficult to classify the research on the history of the Grand Duchy of Lithuania (GDL) Chancery depending on the significance of information contained therein. This information is of equal importance and the only difference is the width of coverage and the depth of analysis of the issues raised in them. The earliest work which contains important (largely topical even today) the observations related to the organization and functioning of Chancery, its role in the GD Ls administration is the masterwork by M.K Liubavskij on a GD Ls Diet. The biggest and continuing interest of the researchers awoke the chancery which arose at the turning period for GDL - Chancery of Vitovt (1392-1430). Different researchers studied this Chancery using various materials and approaches. Among them are A. Vasiliauskas, M. Kosman, R. Capaite and S. Szybkowski. These studies went into several directions: the structure of the Chancery, its personnel, the sphere of use and a formular and a paleography of letters and documents of Vitovt, a letter as a means of written communication this Grand Duke used.