Genetic transformation of plants by useful genes is widely made by Agrobacterium tumifacienes harboring manipulated T-DNA sequences of the binary plasmid. Determining of the integrated T-DNA in the final step of the transformation is critical for understanding the mechanism of this process. The integration of non-T-DNA sequences in transgenic Nicotiana benthamiana plants obtained through Agrobacterium inoculation was investigated. Genomic DNAs from ten plants were subjected to PCR amplification on the sequences located outside the left or right T-DNA borders.  Three plants out of ten were found to have 30 base pair of non-T-DNA sequences including the entire left T-DNA border. The same plants were also contained 107 base pair of the non-T-DNA sequences with the entire right border sequence. The percentage of integrated non-T-DNA sequences represented 30 % whether it belongs to sequences followed the right or left T-DNA side. Integrated T-DNA sequences were confirmed by southern blot analysis.