The aim of this study was to compare the antioxidant activities and active ingredients in ultrasonic-circulating extract powder (UCEP) with hot-water extract powder (HWEP) of log-cultivated Ganoderma lucidum.The DPPH, ABTS, O2-, T-AOA, FRAP assay results showed the UCEP exhibited stronger antioxidant activity in vitro than the HWEP.Meanwhile, the detection of GSH, SOD, MDA in rat liver, ALT, AST, LDH in rat blood, and westem blot for antioxidant proteins of TGF-β1, HO-1 and GSH-Px showed that the UCEP had either similar or a little stronger antioxidant activity in vivo when compared with the HWEP.Further analysis of the active ingredients revealed the UCEP and HWEP had the similar average yields and content of total triterpenoids (TTs), but the former had significant higher (P< 0.05) average yield and content of total polysaccharides (GLPs) than the latter.).These suggested the potential use of UCEP as an antioxidant and liver protectant.