Objective High-performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP/MS) was used to analyze five arsenic species in oyster sauce seasonings, including arsenobetaine (AsB), arsenite As (Ⅲ), dimethyl arsenic (DMA), monomethyl arsenic (MMA) and arsenate As (V). Methods Oyster sauce samples were extracted with 1% nitric acid at 90 ℃ for 3 h, the extract was centrifuged at 8 000 r/min for 10 min, and the supernatant was filtered through 0.22 μm water filtration membrane. A Hamilton PRP-X100 anion exchange column (250 mm×4.1 mm, 10 μm) was used with 10 and 20 mmol/L diammonium hydrogen phosphate methanol solution (containing 2% methanol) as mobile phase for gradient elution. Results The linear range of five arsenic species were good in the range of 0.5-100 μg/L, and the correlation coefficient (r) was above 0.999. The detection limits were 0.1,0.1,0.1,0.2 and 0.2 μg/L, respectively. The recoveries were 83.2%-103.4%, and the relative standard deviations (RSD) were less than 5%. Conclusion The method is simple with a wide linear range and high sensitivity. It is suitable for the determination of oyster sauce samples.