The title compound 1,5-bis(4-methoxyphenyl)-3-(4-methyl-1,2,3-thiadiazol-5-yl)-pentane-1,5-dione (C22H22N2O4S, Mr=410.49) has been synthesized by the reaction of 4-methyl-1,2,3-thiadiazole-5-carbaldehyde with 4-methoxyacetophenone, and its structure was characterized by IR, 1H NMR, H RMS, elemental analysis and single-crystal X-ray diffraction. The crystal of the title compound belongs to monoclinic, space group P21/c with a=11.159(3), b=9.002(3), c=20.192(6), β=93.393(5)°, Z=4, V=2024.6(10) 3 , Dc=1.347 g/cm3 , μ=0.191 mm-1 , F(000)=864, R=0.0333 and wR (I>2σ (I))=0.0840. In this molecule, the 1,2,3-thiadiazol ring is nearly vertical with both phenyl rings, and intermolecular weak hydrogen bonds of C-H…O and C-H…N types together with π-π stacking interactions and interactions between S(1)…N(2) are observed. The above three kinds of interactions extend the molecules into a two-dimensional layer framework. The preliminary biological test showed that the title compound had fungicidal activity. The title compound 1,5-bis (4-methoxyphenyl) -3- (4-methyl- 1,2,3-thiadiazol-5-yl) -pentane- 1,5-dione (C22H22N2O4S, Mr = 410.49) has been synthesized by the reaction of 4-methyl-1,2,3-thiadiazole-5-carbaldehyde with 4-methoxyacetophenone, and its structure was characterized by IR, 1H NMR, H RMS, elemental analysis and single-crystal X-ray diffraction. The crystal of the title compound belongs to monoclinic, space group P21 / c with a = 11.159 (3), b = 9.002 (3), c = 20.192 V = 2024.6 (10)  3, Dc = 1.347 g / cm3, μ = 0.191 mm-1, F (000) = 864, R = 0.0333 and wR (I> 2σ (I)) = 0.0840. The 1,2,3-thiadiazol ring is nearly vertical with both phenyl rings, and intermolecular weak hydrogen bonds of CH ... O and CH ... N types together with π-π stacking interactions and interactions between S (1) ... N (2) The observed three-dimensional interaction of the molecules into a two-dimensional layer framework. The preliminary biological test showed that the title compound had fungicidal activity.