A novel CBF gene was isolated from Brassica campestris L.Longyou 6 by RACE.The fulllength cDNA of CBF (GenBank No.KP974691) was 1 000 bp,contained a 5′UTR of 114 bp,a 3′UTR of 241 bp,and a 645 bp opening reading frame.The deduced protein was 215 amino acids with molecular weight 23.8 kDa and isoelectric point 4.86.On the amino acid sequence level,this gene showed high identities with Raphanus sativus,Ageratina adenophora,Malcolmia scorpioides and Arabidopsis thaliana(93.5%,83.7%,81.0% and 79.0%).RTPCR analysis revealed that CBF were expressed in the stems,leaves,and hypocotyls with almost no tissue specificity.The transcript level of CBF was increased in response to cold,ABA and H₂O₂ stress.However,MAPKK inhibitor U0126 pretreatment 12 h before cold,ABA and H₂O₂ stress,the expression level of CBF was significantly decreased compared with the single stress.The results suggested that CBF played an important role during cold,ABA and H₂O₂ stress in B.campestris.