Two new schiff base N,N’-bis((2-phenyl-2H-1,2,3-triazol-4-yl)methylene)-1,3-pro- panediamine (1) and N,N’-bis((2-phenyl-2H-1,2,3-triazol-4-yl)methylene) -1,4-butanediamine (2) were synthesized by condensation of 2-phenyl-1,2,3-triazole-4-carboxaldehyde with diamine, and characterized by elemental analysis, IR, 1H NMR and MS spectra. Their crystal structures were determined by X-ray single crystal diffraction. Both crystals belong to the monoclinic system, space group P21/c. For compound 1(C21H20N8, Mr=384.45): a = 16.314(3), b =5.7168(11), c = 21.316(4) , β = 105.3(2)°, Z = 4, V = 1917.6(7) 3, Dc =1.332 g/ cm3, F(000) = 808, μ = 0.086 mm- 1, R = 0.0533 and wR = 0.1460; for compound 2 (C22H22N8, Mr =398.48): a = 8.6156(17), b = 5.2964(11), c = 22.665(5) , β = 100.54(3)°, Z = 2, V = 1016.8(4) ?3, Dc = 1.302 g/ cm3, F (000) = 420, μ = 0.083 mm-1, R = 0.0373 and wR = 0.1155. Based on the crystal data, quantum chemistry calculation was performed on the two title compounds by means of Gaussian 98 program. The molecular orbital energies and atomic net charges population were obtained. Furthermore, we analyzed their active atoms. The investigation can serve as a theoretical guide to study the synthesis and activity of the title compounds. Two new schiff base N, N’-bis (2-phenyl-2H- 1,2,3-triazol-4-yl) (2-phenyl-2H-1,2,3-triazol-4-yl) methylene) -1,4-butanediamine carboxaldehyde with diamine, and characterized by elemental analysis, IR, 1H NMR and MS spectra. Their crystal structures were determined by X-ray single crystal diffraction. Both crystals belong to the monoclinic system, space group P21 / c. For compound 1 (C21H20N8 , Mr = 384.45): a = 16.314 (3) b = 5.7168 (11) c = 21.316 (4) β β = 105.3 (2) ° Z = 4 V = 1917.6 = 1.332 g / cm3, F (000) = 808, μ = 0.086 mm -1, R = 0.0533 and wR = 0.1460; for compound 2 (C22H22N8, Mr = 398.48): a = 8.6156 (17), b = 5.2964 Β = 100.54 (3) °, Z = 2, V = 1016.8 (4)? 3, Dc = 1.302 g / cm3, F (000) = 420 and μ = 0.083 mm -1, R = 0.0373 and wR = 0.1155. Based on the crystal data, quantum chemistry calculation was performed on the two title compounds by means of Gaussian 98 program. The molecular orbital energies and atomic net charges population were obtained. The investigation can serve as a theoretical guide to study the synthesis and activity of the title compounds.