Two new lanostane triterpenoids, poriacosones A (8) and B (9), together with eight known compounds were isolated from the sclerotia of Poria cocos (Schw.) Wolf (Polyporaceae), and identified by spectroscopic analysis, including IR, UV, CD, ESI-TOF-MS, HR-SIMS, 1D-, and 2D-NMR spectra. The structures of the new compounds were established as 3alpha,16alpha-dihydroxy-24-oxolanost-7,9(11)-dien-21-oic acid (8) and 3beta,16alpha-dihydroxy-24-oxolanost-7,9(11)-dien-21-oic acid (9).