Abstract: We determined N-nitrosamines in salted fish by gas chromatography-mass spectrometry (GC-MS), optimized the sample preparation conditions, compared the response intensity of N-nitrosamines by SPME and dichloromethane ultrasonic extraction as well as explored the impact of organic solvent, extraction time and times on the determination. By ion selective electrode method, we determined the contents of N-dimethylnitrosamine, N-diethylnitrosamine, N-nitroso-pyrrolidine and N-nitrosamines. Results show that the linear correlation coefficient is 0.999 2, 0.999 1, 0.999 1 and 0.999 2, respectively, with a linear range of 0~10 μg·mL^-1. The method has good reproducibility (RSD≤2.1%, blank spiked recovery is 70%~80%) and high sensitivity (detection limit is 0.038 6 μg·kg^-1, 0.022 7 μg·kg^-1, 0.031 6 μg·kg^-1 and 0.047 8 μg·kg^-1, respectively).