Three new benzenoids, 3-isopropenyl-2-methoxy-6-methyl-4,5-methylenedioxyphenol (1), 2-hydroxy-4,4'-dimethoxy-3,3'-dimethyl-5,6,5',6'-bimethylenedioxybiphenyl (2), 4,4'-dihydroxy-3,3'-dimethoxy-2,2'-dimethyl-5,6,5', 6'-bimethylenedioxybiphenyl (3), together with two known benzenoids, 2,3,6-trimethoxy-5-methylphenol (4) and 2,3-methylenedioxy-4- methoxy-5-methylphenol (5), were isolated from Antrodia camphorata. Our results support that compounds 1-5 potently inhibited LPS (lipopolysaccharide)-induced nitric oxide (NO) production in a dose-dependent manner. The IC50 values of compounds 1, 3 and 5 were 1.8 +/- 0.2, 18.8 +/- 0.6 and 0.8 +/- 0.3 mu g/mL, respectively.