Abstract: GC-MS/MS was applied to the determination of 7 nitrobenzenes in environmental water samples with solidphase extraction based on chloromethylated magnetic polystyrene nanospheres (CMPNs). The optimized conditions found were as follows:① extracting agent:CMPNs material; ② amount of CMPNs:15.0 mg; ③ extraction time:4 min; ④ amount of NaCl:340 g·L^-1; ⑤ amount of acetone (eluant):3 mL; ⑥ elution time:1 min. The HP-INNOWAX chromatographic column was used for GC separation, and the full-scanning mode and the selected ion monitoring mode were adopted in MS. Linear relationships between values of peak area and mass concentration of the 7 nitrobenzenes were kept in the same range of 0.2-4.0 μg·L^-1, with detection limits (3S/N) in the range of 0.006-0.022 μg·L^-1. Precision of the method was tested, and values of RSD (n=6) for 7 NBs found were in the range of 0.30%-5.3%. The proposed method was applied to the analysis of environmental water samples, giving values of recovery in the range of 72.4%-113%.