The aluminum content in seaweed was first researched in out country.The results showed that the aluminum content ranged from 53.2 mg/kg to 2 714.6 mg/kg,especially for laver which had highest average value.The speciation analysis of aluminum was first conducted in seaweed using sequential chemical extraction.There were several forms of aluminum in seaweed and the main speciation was organic aluminum which was stable and not easy to be absorbed by organism.It accounted for 82.5%-87.6% of the total aluminum.The inorganic aluminum which had higher toxicity accounted for only 3.75%-4.94% of the total amount.The present research further proved that it was not enough to use total aluminum as the standard to evaluate the safety of the seaweed,and it was urgent to establish different limitation standards according to different aluminum speciation in order to accurately evaluate the safety of the seaweed and guarantee the healthy development of the seaweed industry.