Sudden changes in environmental factors, primarily temperature, are the main reason for the mass mortalities of benthic organisms that have been recorded in the last ten years. Research and systematic observation of such communities is the main way to obtain a better insight into the state of coralligenous biocenosis and the changes that are happening in the biocenosis under the influence of global climate change. The field research was conducted at five different stations within the Kornati National Park. The main objective was to (i) determine and record the types of corals that are most endangered to increased sea temperatures, (ii) determine the types of indicators of temperature changes and to assess the presence of endangered and legally protected coral within coralligenous community and (iii) determine the conditions prevailing in communities, and thus their possible vulnerability. We found nine different biocenosis with 57 species of coral. The largest number of coral, a total of 41 species, was recorded at the station Mali Obručan, while the lowest number, 34 species, found in the Velika Panitula station. The most common coral species in coralligenous biocenosis are: Caryophyllia inornata, Eunicella cavolini, Leptopsammia pruvoti and Parazoanthus axinellae. At all stations showed a partial reduction of the population (10 to 20% of dead individuals) and visible adverse effect of elevated temperature. The result will be used as a basis for further research and monitoring of biocenosis and corals on the cliffs within the Kornati National Park.