To study the chemical constituents and biological activities of the endophytic fungus Septoriella phragmitis,Silica gel column chromatography,semi-preparative high performance liquid chromatography and other methods were used to isolated and purified compounds.Modern spectrum technologies were applied to identify the structures of thoese isolated compunds.As a result, ten compounds were isolated from the extract of Septoriella phragmitis for the first time,named β-adenosine (1),cyclo-(S-Pro-S-Ile) (2),5-hydroxy-2-methylol-4H-pyrane-4-ketone (3),3α-hydroxyartemisinic acid (4),leptosphaerone C (5),5，6，7，8-tetrahydronaphthalen-1-amine (6),euparin (7),tryptophan (8),cyclo-(Ala-Tyr) (9),β-D-fructopyranocy-(2→6)-D-glucopyranose (10).The α-glucosidase inhibitory activity of the obtained compounds was determined by p-nitrophenyl-β-galactopyranoside method,the PTP1B inhibitory activity was determined by p-nitrophenyl phosphate method,the inhibitory activity of gastric cancer cell HGC-27 was determined by MTT method， and the molecular docking was performed by standard precision docking method.Compounds 6 and 7 showed α-glucosidase inhibitory activity with IC₅₀ values of 8.1 and 8.6 μg/mL,respectively.Compounds 6, 7 and 9 showed PTP1B inhibitory activity with IC₅₀ values of 6.5, 8.2 and 0.5 μg/mL,respectively.Compounds 5 and 6 showed inhibitory activity against gastric cancer cell HGC-27 with IC₅₀ values of 12.2 and 16.8 μg/mL,respectively. Molecular docking showed that compounds 6 and 7 had a strong correlation with α-glucosidase and PTP1B protein,which could be used as anti-diabetic lead compounds for subsequent research.