The total contents of phenolics and flavonoids and the relativeantioxidant and antibacterial activities in different polarity fractions from Atractylodes macrocephala Koidz grown in Qimen (Qi Baizhu) were evaluated. The correlation between total phenolic, flavonoid contents and the antioxidant activities were analyzed. The main constituents of methanol crude extract were identified by gas chromatography-mass spectrometry (GC-MS). The results showed that there were significant differences in the contents of total phenolics and flavonoids, antioxidant and antibacterial activities among different polarity fractions including n-hexane, dichloromethane, ethyl acetate, n-butanol and water fractions (P<0.05). The ethyl acetate fraction had the highest contents of total phenolics \[(139.45±0.19) mg TA/g\] and total flavonoids \[(21.28±2.28) mg QE/g\]. Moreover, it exhibited the strongest reducing power \[(38.95±1.66) mg Vc/g\], ABTS radical scavenging ability \[(302.42±7.51) mg Vc/g\], and DPPH radical scavenging ability \[(51.61±2.59) mg Vc/g\]. The contents of total phenolics and flavonoids demonstrated significant correlations with antioxidant activity (P<0.05). The methanol extract, n-hexane and dichloromethane fractions exerted potent inhibitory effects on E. coli, S. aureus, B. subtilis and P. aeruginos. Hexane fraction presented the best antibacterial effect, and its minimum inhibitory concentration against four common bacterial strains was 1 mg/mL. The methanol crude extract was analyzed by GC-MS, and eighteen compounds were identified, including phenols, alcohols, alkenes and esters, and the major constituents were found to be 3,3'-diamino-4,4'-dihydroxybiphenyl (33.47%), β-eudesmol (28.33%), β-guaiene (5.91%), and 3,3,5,6,7-pentame -thyl-2H-inden-1-one (4.70%).