XV International Scientific Phycological Conference “The Diatoms: present and future research” (XV Diatom School) was held during 23–27 August 2017, in Papanin Institute for Biology of Inland Waters Russian Academy of Sciences, Borok, Yaroslavl reg., Russia. More than 50 diatomologists from Russia, Kazakhstan, Belarus, Ukraine and Israel attended the Conference. The researchers discussed a lot of issues concerning morphology, taxonomy and biology of diatoms, biostratigraphy and using of diatoms in paleoreconstruction, ecology and biogeography of diatoms, problems of diatom evolution, molecular phylogeny and barcoding. The Volume of Proceeding based on the reports submitted to the Conference was prepared. The conference was dedicated to the 70th anniversary of Sergei Ivanovich Genkal, well-known outstanding diatomologist, author of more then 400 papers and monographs, i. e. “Iconographia Diatomologica”.