The antioxidant activities of Panax ginseng have long been known as among the important pharmacological properties of this plant. Although one of the most documented function of glutaredoxin (Grx) in plants is their involvement in the oxidative stress response, there are no reports on Grx in ginseng plants. Therefore, this study was undertaken to assess whether Grx is present in P. ginseng and to characterize the Grx gene coding for these antioxidant information. A cDNA clone containing a Grx gene, designated PgGrx, was isolated from leaves of P. ginseng. The cDNA clone was 493 nucleotides in length and had an open reading frame of 321 bp with a deduced amino acid of 106 residues, possessing a C-S-Y-C active site, which belongs to the Grx subgroup. The PgGrx shows high homology to other Grxs of higher plants. Quantitative reverse transcriptase-polymerase chain reaction has been used to study expression of PgGrx following various abiotic stresses. Findings have revealed that PgGrx is involved in the antioxidative process triggered by environmental changes.