The invention relates to 5,6-diphenyl-1,2,4-triazinic compounds of general formula (I), wherein identical or different R1, R2, R3 and R4 represent a hydrogen, fluoride, chloride or bromine atom, C1 to C12 linear or branched alkyl, C1 A C18 linear or branched hydroxy, alkoxy poly(ethoxy)-alkoxy with a C1 to C4 alkyl fragment and an ethoxy number ranging from 1 to 4, amino or mono or di-alkylamino with a C1 to C4 alkyl fragment group, X is ortho-, meta- or paraphenylene, 4,4′-biphenylene, 2,4- or 2,6- or 3,4- or 3,5-pyridinylene, 2,2′-bipyridinylene, meta- or paraphenylenediamino, ethylenediamine, 2,2′-piperazinylene, diacyl of formula -(R4CO)2-, wherein r represents a phenyl radical, a 3 to 10 carbon, phenanthrene or anthracene atoms alkyl chain except 1,4-bis(5,6-diphenyl-1,2,4-triazin-3-yl)benzene of 2,4-bis(5,6-diphenyl-1,2,4-triazin-3-yl)pyridine and of 2,6-bis(5,6-diphenyl-1,2,4-triazin-3-yl)pyridine, to cosmetic compositions containing said compounds and to the use thereof in the form of sun filters or light-protective agents.