Cyperus rotundus L. (Cyperaceae) has been used as an analgesic and antiinflammatory agent and in the treatment of menstrual disorder in folk remedies. Cyperi Rhizomata, processed and unprocessed, were extracted with methanol and fractionated with petroleum ether, chloroform, butanol, water. The effect of unprocessed Cyperi Rhizoma and processed Cyperi Rhizoma on CCl_4 induced lipid peroxidation and hepatotoxity have been tested in rats. BuOH, water fractions of unprocessed Cyperi Rhizoma enhanced the inhibition of antilipid peroxidative effects in liver lipid. In chemical parameters obtained form serum analysis, butanol fraction of unprocessed Cyperi Rhizoma showed significant decrease in hepatotoxicity. In result, unprocessed Cyperi rhizoma has significant antilipid peroxidative effect and hepatoprotective activity.