In recent years,the world is suffering constantly expanding radioactive pollution. Researchers are seeking specific protective effects against radiation substances to sufficient the patient’s and ordinary people’s needs[1]. Research shows that yeast β-glucan has strong physiological activity such as protective effect of radiation damage,enhancing immune function,inhibiting tumor,anti-oxidation,lower cholesterol and blood fat,etc.[2~6]. This experiment is aim to detect Yeast β-glucan’s protective effect of radiation damage in mice. Researchers are seeking specific protective effects against radiation substances to provide the patient’s and ordinary people’s needs [1]. Research shows that yeast β-glucan has strong physiological activity such as protective effect of radiation damage, enhancing immune function, inhibiting tumor, anti-oxidation, lower cholesterol and blood fat, etc. [2-6]. This experiment is aim to detect Yeast β-glucan’s protective effect of radiation damage in mice.