Abstract: Objective: To study and evaluate the active components, contents and in vitro biological activities of Epimedium sagittatum extract. Methods: Contents of total polyphenols, total flavonoids, total polysaccharides and proanthocyanidins in the extract of Epimedium sagittatum were determined by spectrophotometry, the contents of five flavonoids in the extract were determined by high performance liquid chromatography (HPLC), the antioxidant activity of Epimedium sagittatum extract was evaluated by scavenging DPPH, OH, ABTS⁺ free radical method, and the inhibitory effects on pancreatic lipase, tyrosinase, acetylcholinesterase and butyrylcholinesterase were determined. Results: The contents of total polyphenols, total flavonoids, total polysaccharides and proanthocyanidins in the extract of Epimedium sagittatum were 105.60±0.92, 70.09±0.75, 18.45±1.27, 8.79±0.13 mg/g, respectively. HPLC detected five kinds of flavonoids in the extract. Among them, Icariin and epimedin C contained the highest content, which were 266.16±4.22 and 43.35±0.67 mg/g, respectively. Baohuoside I contained the least, which was 2.54±0.07 mg/g. Epimedium sagittatum extracts had certain free radical scavenging ability. The half-clearing concentrations (IC₅₀) of Epimedium sagittatum extracts on DPPH·, ·OH, and ABTS⁺· were 4.43±0.40, 2.83±0.09 and 2.04±0.08 mg/mL, respectively. The scavenging ability was concentration-dependent. Meanwhile, The IC₅₀ of Epimedium sagittatum extract on lipase, tyrosinase and acetyl/butyrylcholinesterase were 5.97±0.04, 2.27±0.23, 9.27±0.07 and 7.41±0.26 mg/mL, respectively. Conclusion: Epimedium sagittatum extracts was rich in active substances, had a good scavenging effect on DPPH, OH, ABTS⁺ free radicals, and had certain inhibition on pancreatic lipase, tyrosinase, acetylcholinesterase and butyrylcholinesterase effect.