A medical composition for inhibiting the growth of cancer stem cells is disclosed. The medical composition is prepared by mixing herbal medicines with water or alcohol, followed by heating and extraction to obtain a filtrate. One of the medical compositions according to the present invention includes: Coptis chinensis, Scutellaria baicalensis, Phellodendron amourense, Gardenia jasminoides, Radix Glycyrrhizae, and Atractylodes japonica.