Critical study of herbarium and literature date has shown that 55 species o
f 5 genera of downy mildew fungi were found on 64 host plants in steppe Cre
mea. Among those 28 species were recorded for the first time for Crimea and
6 of them - for Ukraine. Paper includes analysis of the downy mildew fungi
distribution in different geographic and geobotanic regions as well as the
ir spreading in the most important biotopes of the steppe part of Crimea. P
eculiarities of the downy mildew fungi species diversify in natural steppe
phytocoenoses and in anthropogenic ruderal ones are discussed.