Objective: Four arsenic species of arsenic in aquatic products were analyzed using ultrasonic-assisted extraction combined with high performance liquid chromatography-atomic fluorescence spectrometry （HPLC-AFS）. Methods: Four arsenic compounds were extracted ultrasonically from the samples using 50%（v/v） methanol-aqueous solution as extraction solvent. The chromatographic separation was performed on Hamilton PRP-X100 anion exchange column using a mixture of 15 mmol/L ammonium dihydrogen phosphate solution with the pH adjust to 6.0 as the mobile phase. Results: Under the optimized conditions, there were good linear relationships in the range of 0～100 μg/L for four arsenic compounds, with correlation coefficients all above 0.998. The limit of detection （LODs） of four arsenic species MMA, DMA,As（Ⅲ）,As（Ⅴ）were 0.82, 0.94, 1.10, 0.78 μg/L respectively. The relative standard deviations were in the range of 0.8%～3.7%. The recoveries ranged from 86.0% to 110.0%. Conclusion: This method is simple, accurate, sensitive, and low reagent consumption costs, can be used for the determination of the arsenic species in aquatic products.