These Proceedings report the scholarly work presented in Leningrad at the largest conference ever held on luminescence. In addition to the large number of delegates, the Conference was dis­ tinguished by strong and balanced representation on the program of papers from capitalist and socialist nations. The Conference was sponsored by the International Union of Pure and Applied Physics and by the Academy of Science of the USSR. As noted in the Opening Ceremony, this Conference is in the series held approximately every three years since 1938. All branches of luminescence are included. It was recognized, during the early stages of organization of the Conference, that there would be difficulties associated with the preparation of an English version of the Proceedings. Until just before the Conference, it was not evident whether translations of the Russian papers would be available and whether facilities would exist at the Conference for a working publication committee to edit the manuscripts. It was not possible, therefore, to make contractual arrangements before the Conference for publication.