Abstract: In order to investigate the content of different forms of aluminum in Enteromorpha clathrata, six kinds of chemical reagents were used for the extraction, and the extraction conditions of these solutions were optimized.The results showed that the optimized extraction parameters were 1.0 mol/L KCl extracting for 4 h, 0.8 mol/L NH₄ Ac extracting for 8 h, 0.1 mol/L ( NH₄) ₃C₆H₅O₇ extracting for 8 h, H₂O extracting for 8 h, 1.0 mol/L HCl extracting for 8 h, and 1.0 mol/L NaOH extracting for 8 h. Under these conditions, the total content of active aluminum in Enteromorpha clathrata was ( 85 ± 3.9) mg/kg, accounting for 6.71% of the total aluminum. The total organic aluminum content was ( 1181 ± 24.7) mg/kg, which cannot be easily absorbed by human body, accounting for 93.29% of the total aluminum. This study provides a reference for scientific evaluation of edible safety of aluminum in Enteromorpha clathrata.