Studies to develop a GC/MS (SIM) method for the determination of 34 pesticides including carbamates and organonitrogen pesticides in foods with solid-phase extraction (SPE) were conducted.Three kinds of SPE columns, a porous diatomaceous earth cartridge column, a diatomite column with a mini C18 cartridge column and a Florisil cartridge column were used successively to clean-up the extract from foods as an alternative to a separatory funnel for liquid-liquid partition. The handling was simpler than the conventional method and gave high recoveries of the pesticides.In GC/MS (SIM), 2 to 4 different fragment ions were selected for each pesticide so that the GC/MS (SIM) identification could be done more accurately for multi-residue analysis of carbamate and organonitrogen pesticides. This simpler method was applicable for 29 pesticides out of 34 with almost the same recoveries and detection limits as the conventional method.