Abstract: This paper aimed to extract the volatile oil from the flowers of Magnolia liliflora, analyze the components of the volatile oil, and explore the biological activity of the volatile oil, in order to provide scientific basis for the development and utilization of this resource. The volatile oil from the flowers of Magnolia liliflora was extracted by using the n-hexane extraction, and its chemical constituents were isolated and identified by gas chromatography-mass spectrometry (GC-MS). Then, the antibacterial activity and antitumor activity of the volatile oil were preliminarily studied through the filter diffusion method and MTT method. The results showed that: A total of 46 chemical components were identified from the volatile oil of Magnolia liliflora flowers, accounting for 92% of the total content of volatile oil, which were mainly alkenes (17 kinds, accounting for 16.9%), hydrocarbon (8 kinds, accounting for 18.43%), esters (6 kinds, accounting for 3.46%), phenolic alcohol (6 kinds, accounting for 4.18%), aldehydes (4 kinds, accounting for 1.9%), heterocyclics (1 kind, accounting for 9.26%), ethers (1 kinds, accounting for 1.09%) and other categories (3 kinds, accounting for 3.76%), among which the component with a relatively high content was Galgaravin (diphenyl tetrahydrofuran derivatives) with a relative content of 9.26%, followed by hexacosane, tetracosane and n-tricosane with the relative contents of 5.05%, 4.57% and 3.28%, respectively. The relative contents of the remaining substances were all lower than 2.5%. The activity detection showed that the volatile oil samples all had antibacterial activity against Bacillus subtili, Escherichia coli, Salmonella typhl and Staphylococcus aureus. When the concentration of volatile oil was 1000.0 μg·mL^-1, the inhibition zone diameter against Bacillus subtilis was 14.8 mm. It showed stronger antitumor activity against the human acute promyelocytic leukemia cell line HL-60 with IC₅₀ of 84.3 μg·mL^-1.