A ruthenium complex is provided. The ruthenium complex is represented by the following Formula (I): ##STR00001## in which, X is a monodentate anion ligand, R.sub.1, R.sub.2, R.sub.4 and R.sub.5 are the same or different substituents and represent alkyl, alkoxy, aminoalkyl, haloalkanes or substituted phenyl group, carboxylic acid group or acid radical salt thereof, sulfonic acid group or acid radical salt thereof, phosphoric acid group or acid radical salt thereof or hydrogen atom. R.sub.3 represents perhalogenated alkyl group, alkoxy, alkyl, amino, halogens, or hydrogen atom. The ruthenium complexes are suitable for being used as dye-sensitizers for fabricating dye-sensitized solar cells.