In this paper, the yield and distribution of 2, 3-butanediol isomers formed during the irradiation of liquors have been investigated and compared with that of the isomers in some ordinary liquors. It has been found that some commercial liquors also contain 2,3-butanediol, but there is difference in the distribution of their optical isomers. 2,3-butanediol is in the forms of meso and dl for irradiated liquor and its ratio(meso/dl)=1. In commercial liquors, 2,3-butanediol is in the forms of meso and 1 and its ratio(meso/1)≤0.5.,G(2, 3-butanediol) values have been determined in various systems. For liquid ethanol saturated with N,2, G(2,3-butanediol)=2.23, 1.46 for the irradiated liquor sample-1 without oxygen and 0.35 for the liquor specimen-1 irradiated under the condition of limited air supply. The results show that (1) the soluble oxygen in liquor can inhibit the formation of 2, 3-butanediol; (2) the other compositions in the liquor can compete with ethanol molecules in reacting with active species(H,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42649288&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42649279&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42649289&type=, OH etc.) and form some unknowns. Therefore, we must pay attention to the hygienic satefy of those unknowns in the irradiated liquor.