The radiation inhibition of bareley and wheat growth was decreased by pre-irradiation treatment with the extracts from the seedings of B. napus L., B. Chinensis L., B. Juncea coss., B. Oleracea L. etc. The radioprotective substance, sinapine, was separated and identified from the extracts. The ESR spectra from sinapine-thymine and sinapine-dTMP all with molar ratio 1:10 also sinapic acid-dTMP with molar ratio 1:10 irradiated and recorded at 77 K confirmed the long range eletron transfer from thymine of dTMP- to sinapine or sinapic acid,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42648301&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42648291&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42648303&type=,guite similar to that by caffeic acid protectors[(Lin Nianyun et al. J. Radiat. Res. Radiat, Process. 1(1), 1(1983)]. Both the radioprotective and anticarcinogenic abilities of sinapine or sinapic acid may be some what better than caffeic acid or ferulic acid.