Abstract: A method has been set up to the determination of n-butyl acrylate in water samples by automated static headspace sampling with gas chromatography-mass spectrometry(GC-MS). The pre-treatment conditions such as equilibrium temperature, equilibrium time and salt ion concentration in the headspace injection process were optimized for the continuous determination. The compound in the water samples was extracted by the headspace at 50℃ after 15 min of equilibration, with the addition of the mass fraction of NaCl of 30%, then separated by a capillary column and analyzed by GC-MS. The retention time of the compound and the selected ions were characterized and quantified by deuterated ethylbenzene used as an internal standard. The correlation coefficient r² of n-butyl acrylate was 0.999 8 in the concentration range from 5 to 250 mg/L, with a good linear relationship. The method was quality controlled by different concentrations (5, 25, 100 mg/L), the recoveries were between 85.7% and 94.6%, and the RSD were between 1.81% and 2.79%, the detection of limit was 0.109 mg/L. The method is simple in operation, highly sensitive and accurate, and good in stability, and is suitable for the determination of the residual amount of n-butyl acrylate in water samples.