Objectives : The Glycyrrhiza new varieties, WONGAM and SINWONGAM, were developed through interspecific cross between Glycyrrhiza glabra and Glycyrrhiza uralensis by the National Institute of Horticultural and Herbal Science, Rural Development Administration in Korea. This in vitro study was undertaken to compare the antioxidant and cytotoxic effects between Glycyrrhiza new varieties (WONGAM and SINWONGAM) and official compendia (Glycyrrhiza glabra and Glycyrrhiza uralensis). Methods : Antioxidant activity was determined by DPPH (1,1-diphenyl-2-picrylhy drazyl), ABTS (2,2-azino-bis (3-rthylbenz-thiazoline-6-sulfonic acid)) diammonium salt, Nitrite radical scavenging assay, and Reducing Power assay. Cytotoxicity was determined by MTT assay and cell morphology was observed by an inverted microscope. Results : The DPPH, ABTS, Nitrite radical scavenging activities and reducing power of Glycyrrhiza glabra, Glycyrrhiza uralensis, WONGAM, and SINWONGAM were evaluated at different concentrations (0, 10, 50, 100, 500, 1000 ㎍/㎖). Glycyrrhiza glabra, Glycyrrhiza uralensis, WONGAM, and SINWONGAM showed similar dose-dependent increase in antioxidant activities. The cytotoxic effects with increasing doses of Glycyrrhiza new varieties and official compendia did not differ in HCT116, HT29, A549, MDA-MB231, PC3, ACHN, and HeLa cells. However, significant difference in cytotoxicity were observed in AGS, MCF7 and Hep3B cells by Glycyrrhiza glabra, Glycyrrhiza uralensis, WONGAM, and SINWONGAM. Conclusions : These results showed that Glycyrrhiza new varieties and official compendia acts as a potent antioxidant. Also, the finding that equivalent cytotoxic potency was observed in a cell dependent manner. Our study suggests that Glycyrrhiza new varieties may offer a wide-variety of health benefits.