Abstract: The series of nine amides of substituted 8-hydroxyquinolines were prepared. The synthetic procedures of compounds are presented. All the prepared quinoline derivatives were analyzed using RP-HPLC method for the lipophilicity measurement and their lipophilicity were determined. The prepared compounds were tested for the reduction of chlorophyll content in Chlorella vulgaris Beij. Several compounds showed biological activity comparable with or higher than the standard 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU). The relationships between the lipophilicity and the chemical structure of the studied compounds are discussed as well as structure-activity relationships (SAR) between the chemical structure and the biological activities of the evaluated compounds.