This paper researches into the absorption spectra of phoxim in the presence of cationic surfactant,and finds out that cationic dye calcein in neutral condition will reaction with phoxim under the actions of appropriate surfactant.After phoxim is added,the absorption intensity is reduced with the increase of phoxim concentration,and both are good proportional to the relation.And the linear range is 0.05~6.00 mg/L and the detection limit is 0.008 mg/L.In view of the results,a new method for determination of phoxim pesticide is provided,which is applied to determine total-residues of phoxim in vegetables,rice and soil,and the average recoveries ranges 80.0%~93.0%.