The all optimize stoichiometric calculation has been done about five kinds of sulfonamide-drugs by quantum chemical density functional theory(DFT)on the level of 6-311+ + G(d,p),which has included SN,ST,SD,SG and SMP molecule.According to the calculated results,molecular geometric structure,infrared spectrum,dipole moment and the atom charge distribution have been circumstantiately analyzed and compared.Combined the front orbit theory and the molecular energy,we have found out the absolute bioactivity order was:SMPSDSTSGS...