Most traditional Chinese medicine prescription dosages are imprecise. This study analyzes the toxicities and adverse effects of a combination the active ingredients of licorice and Kushen medicine: oxymatrine (OMT) and diammonium glycyrrhizinate (DG). The median lethal dose (LD₅₀) and mortality were analyzed in single-dose OMT (or DG) intraperitoneally injected mice with or without combination DG (or OMT). Body weight changes as well as levels of serum sodium and potassium, alanine transaminase (ALT), aspartate transaminase (AST), creatinine, and urea were measured in mice treated with a daily dose of OMT and/or DG for 14days. This study showed that the LD₅₀ of OMT for males and females were 347.44 and 429.15mg/kg, respectively. The LD₅₀ of DG were 525.10 and 997.26mg/kg for males and females, respectively. DG significantly decreased the mice LD₅₀-induced mortality of the OMT, however OMT did not succeed in reducing the LD₅₀-induced mortality rate of DG. The combination of OMT and DG obviously attenuated the changes of the body weight, serum sodium, and potassium induced by DG or OMT alone. These results suggested that toxicity and adverse effects of the OMT was significantly attenuated by DG. The OMT neutralized the adverse effects of the DG, but not the toxicity.