The antiproliferation activity of the ethanol extract of A. cinnamomea mycelium on hepatocellular cancer cells HepG2 was found to be associated with aroma intensity of the broth during fermentation. We hypothesized that some of the volatile compounds are the precursors of the key bioactive component 4-acetylantroquinonol B of this fungus. The major volatile compounds of A. cinnamomea were identified by GC/MS, and they are oct-1-en-3-ol, linalool, methyl phenylacetate, nerolidol, γ-cadinene and 2,4,5-trimethoxybenzaldehyde (TMBA). TMBA and nerolidol were further selected and used as supplements during fermentation. It was found that both of them could increase the production of 4-acetylantroquinonol B and enhance the antiproliferation activity of the fungus. In addition, the TMBA was identified as the most promising supplement for increasing the bioactivity of A. cinnamomea during cultivation.