Eleven phenolic Compounds have been isolated from the ethanolic extract of Selaginella doederleinii by a combination of Chromatographic techniques. These are five lignans: (-)-lirioresinol A, (-)-lirioresinol B, (+)-wikstromol, (-)-nortracheloside, (+)-matairesinol (1), two phenylpropanones: 3-hydroxy-1-(3-methoxy-4-hydroxyphenyl)-propan-1-one (2), 3-hydroxy-1-(3,5 -dimethoxy-4-hydroxyphenyl)-propan-1-one (3), and four biflavonoids: amentoflavone, 7,7″-di-O-methylamentoflavone, 7,4′,7″,4‴-tetra-O-methylamentoflavone, and heveaflavone (4). Compounds 1, 2, and 3 are novel natural secondary metabolites. Their structures were deduced from their spectral data (mainly 1H-NMR, mass, and CD). Lignans are described here for the first time in the family Selaginellaceae. Their cytotoxic activity against L 929 murine cells accounts for the use of the plant in traditional Chinese medicine as an anticancer agent.