The authors studied the electronic condition of comb-shaped copolymer of polycarboxylic acid type hyperdispersant adsorbed on the surface of atrazine particles with X-ray photoelectron spectroscopy (XPS). The thickness of the adsorption was calculated. The results suggested that after adsorbing the dispersant, the peak intensity of N(1s) and Cl(2p) of the interface of atrazine particle decreased sharply, while the absorption of Cl(2s) almost diminished. Meanwhile the peak intensity of C(1s), O(1s) and Na(1s) increased obviously owing to the second emission of C, O, and Na from the dispersant molecule. After adsorption, the dispersant formed a favorable protecting membrane on the surface of atrazine particles whose thickness was about 24 nm. The authors also studied the surface state of the sample with scanning electron microscope (SEM). The results of which showed that after adsorption, the atrazine particles became smaller and their dispersion was in good order. These changes allowed the atrazine particle to have a stable suspension property. This study provided significant information for the application of environment friendly atrazine suspension concentrate.