A total of 1 679 bp genomic DNA of BnCYP78A8 was first cloned from Brassica napus using Genomic walking method and then the coding sequence was cloned using special primers.The genomic DNA sequence is 1 679 bp,containing one intron and two exons.The coding sequence is 1 605 bp，coding for 534 amino acids.Sequence alignment of amino acid showed that BnCYP78A8 shared high identity （88%) with AtCYP78A8 in Arabidopsis thaliana.Bioinformatics analysis indicated that BnCYP78A8 protein contain one cytochrome P450 cysteine heme-iron ligand signature and one transmembrane domain.The real-time PCR results demonstrated that BnCYP78A8 expressed in all indicated tissues of Brassica napus,and its expression in root was higher than that in other tissues,suggesting that BnCYP78A8 might be involved in root growth.