A disk format solid phase extraction method for the determination of the pesticides, by gas chromatography/mass spectrometry (GC/MS) with electron ionization (EI) is described. This method provides good linearity of the calibration curve and repeatability. The correlation coe‹cients of calibration curve were estimated to be from 0.981 to 0.999 for these pesticides in the concentration range from 0.2 mg/L to 2 mg/L. These compounds were adsorbed on a disk format solid phase from river water and rain water. A capital acetone and hexane was investigated as solvents for elution of these compounds adsorbed on the solid phase. As a result, a capital acetone and hexane turned out to be very eŠective and a high recovery (about 100) was obtained for these pesticides in distilled water. This method was successfully applied to analyze the pesticides in river water and rain water.