This article is an introduction to the description and analysis of the electronic correspondence of the author with I.S. Kon, held in 2005-2011. Kon belongs to a narrow group of sociologists who stood at the origins of Soviet sociology. For many years, Kon has successfully worked in different areas of sociology, at the same time he is a recognized expert in the history of Russian and Western sociology. All this: 1) makes Kon a unique expert in the field of studying the entire period of development of Russian sociology, and 2) determines the historical, sociological and methodological value of his letters. Let us pay attention to the fact that the study of the correspondence of sociologists is a poorly studied topic, but there is a tendency to increase attention to it. The total number of letters is about 200. The texts of 39 letters for 2005-2006 are given. The history of correspondence and its content is briefly considered.