Abstract: For developing a method to reduce the emanation coefficient of Rn in materials, emanation coefficient of Rn in geological uranous materials such as zircon, uranium-bearing ore, etc is measured. Heating is used to study the effect of heating temperature on emanation coefficient of Rn. The results show after heating, the emanation coefficient of Rn in above materials decreases gradually according to the heating temperature increasing. Heating can reduce the emanation coefficient of Rn effectively, which can be used as a new measure to defend against radon and radon daughters.