Abstract: OBJECTIVE To analysis the chemical composition of the absolute oil from the medicinal mushroom Phellinus pini, and to evaluate its antioxidant and antitumor activities. METHODS The absolute oil was isolated from Phellinus pini by ether, and its chemical composition were analyzed by GC-MS. The antioxidant activity was evaluated by 1,1-diphenyl-2- picrylhydrazino(DPPH) free radical scavenging test, and the antitumor activities were evaluated by MTT method. RESULTS Eleven components in the absolute oil from Phellinus pini were identified, accounting for 12.25% of the total amount of the absolute oil. The biological activity test showed that the absolute oil had a certain antioxidant activity, with the IC₅₀ value of 0.82 mg·mL^-1 against DPPH radical scavenging, but the inhibitory activities against the tested tumor cell lines (Hela, A549 and B16F10) were not obvious, all with the IC₅₀ values > 100 μg·mL^-1. CONCLUSION The absolute oil of Phellinus pini has a certain antioxidant activity, and the antioxidant activity increased with the increase of concentration of the absolute oil, but its antitumor activities are not obvious.