This book contains 17 crystals structures solved by X-Ray Crystallography. These crystals are 1)¿-4(chlorophenoxy)-¿-(1,1-dimethylethyl)1H-1,2,4-triazole-1-ethanol(tridimenol)2) ¿-4(-idophenoxy)-¿-(1,1- dimethylethyl)1H-1,2,4-triazole-1-ethanol 3) N ¿(2,6 dime-thylphenyl)-N-(2-Keto-1-methylbuty1)-3-hydroxypropanamide 4) ¿-(phenoxy)-¿-(1,1- dimethylethyl)1H-1,2,4-triazole-1-ethanol 5) Tricyclazole 6) SULPHUR 7) Thiophanate Methyl 8) dimethomorph 9) hexaconazole 10) Tetra methyl thiuram disulphide 11) 3, 5-dimethyl 1, 3, 5-thiadiazine-2-thione 12)cis N ¿(1,1,2,2-TETRACHLOROETHYLTHIO)-4-CYCLOHEXENE-1,2 DICARBOXIMIDE 13) bis (dim ethyl thiocarbamoyl) disulphide 14) monceren N-((4-chlorophenyl)methyl)-N-cyclopentyl-N'-phenylurea 15) Chlorothalonil 16)5, 6-dihydro-2-methyl-1, 4- oxathiin-3 ¿caboxanlido (Vitavax)17) COMPARATIVE STUDY OF Tridimenol, Tricyclazole and Tridimefon fungicides. In order to design rationally more effective synthetic fungicides, it is necessary to Analyses the three dimensional structure of these compounds and it possible the receptor molecule. find the structure substitute can be made.