Antrodia camphorata (AC) is a fungus native to Taiwan which is believed to be effective in preventing diseases. Recent reports demonstrate that AC induces apoptosis of various tumor cells. In this study we investigated how ethanol extract of AC affect metastatic activity in CL1‐0 and CL1‐5 lung cancer cells. The underlying mechanism was also investigated via Western blotting. Our results demonstrated that ethanol extract of AC dose and time‐dependently inhibited the migration and invasion of CL1‐0, CL1‐5 cells under non‐cytotoxic concentrations. However, ethanol of AC demonstrated more inhibition on CL1‐5 than CL1‐0. When treating with AC, MMP‐9 and MMP‐2 activity were reduced in the gelatin zymography assay. By Western blot analysis, treatment with AC decreased phosphatidylinositol3‐kinase/AKT, MMP‐2 and MMP‐9 expression in CL1‐0 and CL1‐5 cells. AC also exerted an inhibitory effect on the phosphorylation of extracellular signal‐regulated kinases 1 and 2 and inhibition of activation of nuclear factor kappa B, c‐Fos, and c‐Jun. So, according to these data, the growth inhibition of lung cancer cells by AC was mediated by induction of metastasis and cell proliferation related proteins. As shown by the above results, Antrodia camphorata may be a powerful candidate in developing preventive agents for cancer metastasis.