Gaocao (Radix Glycyrrhiza) belongs to Leguminosae， whose root and rhizome is used in the formulation of Chinese medicine. Gancao， sweet in taste and neutral in nature， enters channels of heart， lung， spleen， stomach， and contains various active components. Gaocao can dispel phlegm to stop coughing， alleviate pains， suppress virus and bacteria， and harmonized other medicines. The article is a literal review of the clinical application of Gancao， including the contraindications.