Two series of 4,6-disubstituted 1,3,5-triazin-2-amines were prepared by cesium carbonate-promoted cotrimerization of aromatic nitriles with guanidine and the reaction of (hetero)arylnitriles with N-acetylguanidine. The first series of 4,6-bis-(hetero)aryl-1,3,5-triazin-2-amines was synthesized in yields of 56-85% by adapting a traditional approach that starts from readily available substrates but requires strong and hard-to-handle bases as well as presents serious scope limitations. In this line, the method developed here used a mild base and overcame the scope limitation for p-substituted benzonitrile with electron-releasing group. The second series of 4-(hetero)aryl-6-methyl-1,3,5-triazin-2-amines comprises unsymmetrically substituted symmetrical triazines which were synthesized in yields of 58-75%. In summary, this work highlighted a synthetic method which tolerate broad range of substrates, including o- and p-substituted benzonitriles as well as heteroaromatic nitriles.