The coloration, viscosity increasing and gaseous products induced by γ-ray in epoxy compounds have been reported previously. The changes of epoxide equivalent, hydroxy, carbonyl, unsaturated bond, degree of polymerization and gaseous products in E 51-618 epoxy resin γ-irradiated have been examined and evaluated by means of IR, UV, NMR and GC/MS, etc. The radiation induced products such as dipolymer(compound Ⅰ,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42650800&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42650819&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42650818&type=,), oxidized hydroxy compound (compound Ⅳ,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42650811&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42650822&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42650821&type=,) and gaseous products (compound Ⅴ,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42650813&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42650815&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42650824&type=,) have been first found. The radical reaction machenism in above system was discussed.