Hedyotis corymbosa L., with local name rumput mutiara, is an anti-inflammatory, anti-cancer and hepatoprotective traditional medicine. The ethanol extract of H. corymbosa L. shows inhibitory activity to humanYMB-1 breast cancer cell line with an IC50 of 6.51 μg/mL. The methylene chloride fraction shows a potential cytotoxic activity with an IC50 of 2.75 μg/mL. To obtain a lead compound, the extract was further purified by column chromatography. A pure compound is obtained which shows inhibitory activities against YMB-1, HL60 and KB human cell lines with IC50 values of 0.7; 11.0 and 104.2 μg/mL, respectively. Based on the 1D and 2D FT-NMR data, the isolated compound is an asperuloside.