Using Edinburgh FLS920P spectrometer, the authors obtained the UV-visible spectrum and fluorescence spectrum of parathion, metaphos and isocarbophos in their solution of methanol and ethanol respectively，and discussed their spectral characteristics and their mechanisms. Results show that they all have obvious absorption and fluorescence under the excitation of ultraviolet. The absorption peaks of parathion, metaphos and isocarbophos in their methanol and ethanol solution respectively are at 304 nm/298 nm， 304 nm/304 nm and 286 nm/286 nm. The peak wavelengths of fluorescence are at 404 nm/403 nm, 407 nm/402 nm and 423 nm/415 nm, fitting fluorescence characteristics of conjugated aromatic compounds that the peak will have red shift　with　the increasing solvent polarity. The results may contribute to the application of spectral technique in the distinction of pesticides and detection of residues of pesticides in the area of food security supervision.