Application of an in vitro anticancer bioassays were guided fractionation of bioactive higher plant and extracts led to the isolation of a variety of natural products with potential anticancer activity. Presented herein are interesting structural features of the ethyl acetate mesocarp active fraction of Phaleria macrocarpa, fam. Thymelaeaceae. These fractions were fractionated by using open column silica gel chromatography following identification, resulted in the isolation of known lignan 5[4(4-Methoxy-phenyl)-tetrahydrofuro[3,4-c] furan-I-yo-benzene-I and also unidentified fatty acid compound. Their structures identification were based on chemical and spectroscopic methods such as ultraviolet-visible (UV-Vis) spectra data, fourier transform infra red (FTIR) spectrometric, liquid chromatography-mass spectrometry (LC-MS), the proton nuclear magnetic resonance spectral data ( l ) H-RMI and combination of 2D I H, IH-COSY, TOCSY and NOESY RMI. Using taxonomy chemotaxonomy Dahlgren and Conqruist system approached indicate that the lignan compound have cytotoxic activity.