Abstract:ABSTRACT: Objective To understand the total arsenic content and five arsenic forms in 4 kinds of dried algae in Liaoning Region, and analyze and compare them Methods The 4 kinds of dried algae samples were treated by dry digestion method. The content of total arsenic was determined by atomic fluorescence spectrometry, and the content of arsenic speciation was determined by liquid chromatography atomic fluorescence spectrometry (LC-AFS). Results Results the total arsenic content of 4 kinds of dried algae was different. The order of total arsenic content was Laminaria japonica>Sargassum fusiforme>Porphyra yezoensis>Undaria pinnatifida. The difference was related to species attributes, arsenic metabolism and growth characteristics. Arsenic betaine was the main form in four kinds of dry algae, and the content was between 20.97 and 35.04 mg/kg; Low levels of dimethyl arsenic and methyl arsenic were detected. Inorganic arsenic was not detected in Porphyra; The inorganic arsenic content of kelp and Undaria pinnatifida was low. The inorganic arsenic content in Sargassum fusiformes is significantly higher, with lower levels of arsenite and arsenate as the main form. Conclusion According to the inorganic arsenic limit (0.5 mg/kg) of aquatic animals and their products in GB 2762-2022 national standard for food safety, the inorganic arsenic content of Porphyra, kelp and Undaria pinnatifida was lower than 0.5 mg/kg, which was at a safe level; The content of inorganic arsenic in Sargassum fusiforme is significantly higher, which is mainly related to its strong enrichment ability of arsenic, low efficiency of organic transformation of arsenic forms, and arsenic accumulation effect caused by the growth environment and long breeding cycle. Therefore, it should be purchased and eaten with caution.