PURPOSE: A method for enhancing anticancer effect of red ginseng extract is provided to increase ginsenoside content in the red ginseng extract and enhance anti-cancer effect by apoptosis. CONSTITUTION: A method for manufacturing red ginseng extract having enhanced anticancer effect comprises: a step of adding a radical generating agent to red ginseng extract; and a step of irradiating radiation to the solution. The red ginseng extract contains the ginsenoside. The red ginseng extract is pulverized red ginseng extract or red ginseng extract. The pulverized red ginseng extract is obtained using water, alcohol or alcohol solution. The radical generating agent is hydrogen peroxide, acetyl hedroperoxide, or ascorbic acid. The radiation is irradiated by gamma ray, electronic beam, UV or X-ray in 1-10 kGy. A pharmaceutical composition or health food for preventing and treating cancer contains red ginseng extract as an active ingredient.본 발명은 방사선을 이용한 홍삼(red ginseng)액의 항암효과 증진 방법에 관한 것으로서, 구체적으로 홍삼농축액을 메탄올에 추출한 후, 과산화수소를 첨가하고 감마선을 조사하여 항암효과를 증진시키는 방법에 관한 것이다. 따라서 복잡한 처리 과정 없이 방사선 조사기술을 이용하여 홍삼액 내 진세노사이드 함량이 높아졌고, 아폽토시스에 의해 유발된 항암효과가 증진되어, 항암제로 유용하게 사용될 수 있다.