Li, J (reprint author), Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China.
The radiation background of BES detector depends on the radiation level in the BES experimental hall. The way to reduce radiation level of experimental hall is very important for suppression of radiation background of BES and improvement of detection efficiency. The radiation level, the source and distinguishing feature of radiation background have been studied. The way to reduce the radiation has been discussed.