[Objective] To isolate endophytic fungi with acetylcholinesterase (AChE) inhibitory activities from Huperzia serrata(Thunb.)Trev. [Method] Stems, leaves and roots of H. serrata were collected from the open field. Then, they were inoculated on PDA culture medium after the surface sterilization. Based on the isolation of endophytic fungi, shaking flask fermentation was conducted; and fermentation products were extracted by ultrasound. Inhibitory effects in vitro of fermentation products on AChE were detected by DTNB method. [Result] A total of 194 endophytic fungi were isolated from the roots, stems and leaves. After the fermentation in potato glucose liquid medium (PDB), in vitro AChE inhibitory activity was detected in endophytic fungi fermentation extracting liquid. 31 endophytic fungi showed in vitro AChE inhibitory activity. Among them, 13 strains had relatively strong inhibitory activity, with the inhibitory rate being 50.2%-80.5%. 9 strains were isolated from the H. serrata stems; and 4 strains were isolated from leaves. [Conclusion] Endophytic fungi could be isolated from the H. serrata. The fermentation products of the endophytic fungi showed relatively strong in vitro inhibitory activity to AChE, which might be one of the effective approaches to find the inhibitory drugs of AChE. [Objective] To isolate endophytic fungi with acetylcholinesterase (AChE) inhibitory activities from Huperzia serrata (Thunb.) Trev. [Method] Stems, leaves and roots of H. serrata were collected from the open field. Then, they were inoculated on PDA culture Based on the isolation of endophytic fungi, shaking flask fermentation was conducted; and fermentation products were extracted by ultrasound. Inhibitory effects in vitro of fermentation products on AChE were detected by DTNB method. [Result] A total of 194 After the fermentation of potato glucose liquid medium (PDB), in vitro AChE inhibitory activity was detected in endophytic fungi fermentation extracting liquid. 31 endophytic fungi were isolated from the roots, stems and leaves. , 13 had had had relatively strong inhibitory activity, with the inhibitory rate being 50.2% -80.5%. 9 were were isolated from the H. serrata stems; [Conclusion] Endophytic fungi could be isolated from the H. serrata. The fermentation products of the endophytic fungi have been relatively in vitro inhibitory activity to AChE, which might be one of the effective approaches to find the inhibitory drugs of AChE.