Abstract: The crystal of (+)-A Triadimenol (baytan) belongs to monoclinic system with space group C_2~2-P2_1 and cell parameters a=1.0543(1) nm, b=0.8202(1) nm, c=0.9778(1) nm, β=113.048(7)°. There are two molecules in each unit cell, Z=2. The X-ray diffraction data were collected on PW-1100 four-circle diffractometer, with CuKα radition. The number of independent diffraction data amounts to 1610, of which 1524 are observable reflections. The crystal structure has been determined by direct method (RANTAN) and refined by full-matrix least-square method to R=0.065. The absolute configuration has been assigned by direct measurement of 18 enantiomer sensitive Bijvoet reflection pairs. X-ray structure analysis shows that absolute configuration of (+)-A triadimenol is 1R, 2S, the triazole ring has an aromatic property.