Abstract: A method for the determination of acrylic acid in water by ion chromatography with gradient elution of hydroxide ion was established. The water sample was collected in plastic bottles or glass bottles, and could be stored below 10 ℃ and analyzed within 48 h. The water sample with pH above 7 was purified quickly by Na column, Ag column and C₁₈ column in sequence. Acrylic acid was separated by gradient leaching with an automatic hydroxide ion eluent generator at flow rate of 1.0 mL·L^-1 and column temperature of 30 ℃, and then determined by suppressed conductivity detector and quantified by external standard method. Under the optimal conditions, linear relationship between values of peak area and mass concentration of acrylic acid was found within 20.0 mg·L^-1, with detection limit of 0.02 mg·L^-1. RSDs (n=6) of the determined values for the actual samples with different mass concentration ranged from 1.6% to 7.2%. Recovery test was made for groundwater, surface water, industrial wastewater and domestic sewage, giving results in the range of 96.8%-124%.