［Objective］ A series of N-alkylated indole derivatives（NAID） were designed and synthesized，and their antifouling activity against fouling organisms was evaluated.［Methods］Different carbon chain lengths were introduced at the amino position of indole via N-alkylation reaction. The structures of target compounds were confirmed by IR and ¹H NMR. Their antifouling activity was assessed against the Navicula minima，mussel byssus and barnacle larvae. Molecular docking wasemployed to explore the interaction mechanism between alkylated indole and acetylcholinesterase.［Results］ Bioassay results demonstrated that N-alkylation significantly enhanced the antifouling activity of the indole derivatives. NAID. e，containing a 6-carbon chain，showed optimal performance， with an EC₅₀ of 0. 8 μg/mL against diatom attachment，an LC₅₀ of 1. 3 μg/mL against barnacle larvae， and 77% inhibition of mussel byssus attachment at 10 μg/mL. Molecular docking revealed that NAID. ecould form dual π -alkyl interactions with PHE331 and TYR334 in the active site of AChE.［Conclusion］ A series of indole derivatives with marked antifouling activity were successfully synthesized，providing promising candidate compounds for the development of novel antifouling agents.