In this paper, spectral identification of methamidophos artificial antigen was reported. The results showed that UV absorbance spectrum of artificial antigens of BSAM changed compared with carrier BSA and hapten Met. The absorbance peaks which are similar to P-O-C and P=O moiety in IR spectrum of Met molecule appeared in the IR spectrum of the artificial antigens of BSAM. The chemical shift of the artificial antigens of BSAM is the same as that of standard Met in 31P NMR spectrum. Phosphor concentration of the artificial antigens of BSAM was determined by phosphor molybdate blue spectrophotometry, and then conjugating ratio was calculated, to be 11. The results obtained with the above four spectrum methods showed that the artificial antigens of BSAM was synthesized successfully.