Mercuric chloride was introduced per Os in albino rats (Rattus norvegicus) as per the LD50 (9.26 mg/kg b.w.). The assessment of mercuric chloride toxicity was done both after acute (0.926 mg/kg b.w.) and sub-acute (0.033 mg/kg b.w.) per Os treatment, while Panax ginseng was also introduced (10 mg/kg b.w.) per Os in the albino rats separately. Mercuric chloride treatment significantly increases mercury retention in liver and blood serum along with increase in liver weight, while Panax ginseng alone caused significant decrease in liver weight and mercury retention in liver and blood. Increase in mercury retention in blood serum and liver is due to the reactivity between –SH protein of blood serum and liver with oxidized form of mercury (Hg++), while decrease in Panax ginseng treatment is due to antioxidant activity of Panax ginseng the ginsenosides. Moreover, mercuric chloride followed by Panax ginseng and Panax ginseng followed by mercuric chloride treatment revealed significant modulation for raised mercury retention and liver weight towards normal level along with blood serum and liver changes. The results suggest a modulating role of Panax ginseng extract against raised mercury concentration in blood serum and liver under stress of mercuric chloride.