Abstract: GC. GC/MS-SIM analysis of seven main chemical warfare agents in water and rice by GCMS-SIM techniques was developed. The water samples were extracted with dichloromethane, and The extracts were concentrated to I ml under a gentle stream of nitrogen. The corn samples were extracted with distilled water. The extracts were centrifuged, passed through C18 solid-phase columns, elated with 2 ml acetonitrile, and Then determined with external standard method by GC/MS with selected ion monitoring (SIM). The method of sample treatment is convenient and suitable for analysis of traces of chemical warfare agents in drinking water and corns under The field condition.