The first effort to prepare a critical edition of the whole work of J. A. Comenius Originated at the outset of the twentieth century. However, from the planned volumes only eight volumes were published between 1910-1938. New call for a scholarly edition of collected writings of Comenius was connected with the first great celebration commemorating significant Comenian jubilee the late fifties of this century. Within the Czechoslovak Academy of Sciences editorial board was founded. The editiof J. A. Comenii Opera omnia has started, at first attached to the Institute for the Czech Language, between 1971— 1990 in Comenius Institute of Education, recently in the Institute of Philosophy. The critical edition of J. A. Comenii lépera omnia which has represented the Czech scholarly work has been based on the following principles: To edit the writings in the language in which they were written by Comenius, i. e. in Latin, Czech, exceptionally in other languages, e. g. based on the last preserved original printed or MSS version. The original version of Comenius has been transcribed, accompanied by critical notes and by a commentary, by general information, always in the language of the original version. Every volume has contained also indexes and illustrations. Each volume has been prepared by a team of editors supervised by main editors, concerning the text and by main editors for commentaries. Between 1969-1989 13 volumes were edited in the pubHshing house Academia (1, 2, 3, 4, 9/1, 11, 12, 13, 14, 15/1, 15/11, 17,18) and this article describes their content.