Over 3000 rice plants with T-DNA carrying a Ds element were constructed by Agrobacterium tumefaciens mediation.Using inverse PCR methodology,590 unique right flanking sequences of T-DNA(Ds)were retrieved from independent transformants and classified into six main types on the basis of the origin of filler DNA between the right border of T-DNA and flanking sequence of rice genome.Type I sequences were the most common and showed canonical integration that T-DNA right border was followed by rice genome sequence with or without filler DNA of no more than 50 bp,while type Ⅱ sequences displayed a vector-genome combination that T-DNA right border was followed by a vector fragment and then connected with rice genome sequence.The location and distribution of 340 type Ⅰ and Ⅱ flanking sequences on the rice chromosome were determined using BLAST analysis.The 340 Ds insertions at an average interval of 0.8 megabase(Mb)constructed a basic framework of Ds starter points on whole rice chromosomes.The frequency of T-DNA(Ds)inserted into the exons of predicted genes on chromosome one was 21%.Knowledge of T-DNA(Ds)locations on chromosomes will prove to be a useful resource for isolating rice genes by Ds transposon tagging as these Ds insertions can be used as starting lines for further mutagenesis.