Twelve ergostanoids, named antcamphins A-L (1-12), together with 20 known triterpenoids, were isolated from fruiting bodies of the medicinal fungus Antrodia camphorata. Compounds 1 and 2 represent the first examples of norergostanes isolated from A. camphorata, and compounds 3 and 4 are the first pair of cis-trans isomers of ergostane-type triterpenoids containing an aldehyde group. Compounds 5-12 are four pairs of C-25 epimers. The structures of 1-12 were elucidated on the basis of extensive spectroscopic data analysis including NMR and HRESIMS. Particularly, the absolute configurations at C-25 for 5-12 were determined by the modified Mosher's method. These triterpenoids exhibited weak cytotoxic activities against MDA-MB-231 breast cancer cells and A549 lung cancer cells, but did not inhibit the growth of normal cells in the sulforhodamine B assay.