[Objective] The research aimed to isolate flanking sequences adjacent to the transgenic T-DNA in Brassica napus by an improved inverse PCR method.[Method] Using single clone of transgenic FS4 in Brassica napus as the research materials,total DNA was extracted from transgenic Brassica napus by using modified CTAB method.After enzyme digestion and purification,self-joining was made.Two circles of nested PCR and the sequence alignment were carried out.[Result] A fragement with the size of 4.0 kb was amplified ...