The ,γ, radiation induced polymerization of styrene in the presence of ethanol was studied at dose rate of 5×10,17, eV/ml min. The result showed that the radiation induced polymerization of styrene was sensitized by ethanol. The experimental results were in agreement with the theoretical calculation of WAS equation,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42649506&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42649508&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42649507&type=,gotten G,fi,=0.1, G,gi,=4.0, α=0.18,The mechanism of sensitization is proposed as proton transfer reaction:,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42649509&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42649512&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42649510&type=,St• is the initial center for radical polymerization of styrene.