The present invention relates to a pharmaceutical composition for the prevention and treatment of cancer comprising daurinol as an active ingredient, more precisely a pharmaceutical composition for the prevention and treatment of cancer comprising daurinol isolated from the medicinal plant of Mongolia, Haplophyllum dauricum or Haplophyllum cappadocicum, as an active ingredient. Daurinol can selectively block the S phase of cancer cell cycle to disturb the cycle and induce apoptosis stepwise, resulting in anticancer effect. Therefore, daurinol of the present invention can be used as a positive control chemical in the research and development field of cancer biology especially for cancer therapy and prevention. Daurinol also can be a promising candidate for a novel cell cycle blocker and a novel apoptosis inducer which could be effectively used for the prevention and treatment of cancer in the end.