Fifteen 4-hydroxycoumarin derivatives were synthesized. Seven of them are described for the first time. By means of X-ray crystal structure analysis of 4-hydroxy-3-[(2-#1086x#1086-2#1053-chromen-3-yl)-(2-#1077thoxycarbonylphenyl) methyl]-chromen-2-#1086ne (3) and 3-[2,6-dichlorophenyl) (#1077thoxy) methyl]-4- hydroxy- 2#1053-chromen-2-#1086ne (6) were confirmed the structure of these compounds previously by us. A comparative pharmacological study of the anticoagulant effect with respect to warfarin showed that the synthesized compounds have different anticoagulant activities. The QSTR model derived on the set of seventeen 4-hydroxycoumarin derivatives indicates that low i.p. toxicity could be achieved for a compound with large surface, unbranched molecule, with electronegative neighbour substituents and missing phydroxylgroup in the aldehyde fragment of the molecule