This experiment was carried out to confirm the stability of bar gene introduced into petunia plant through Agrobacerium-mediated transformation. Twenty-five transgenic plants T plants, back cross (BC) populations to wild type and Fplants between different T plants were prepared, and polymerase chain reaction(PCR), PCR-Southern blot analysis, and field test with 0.1% Basta treatment were done. The results of PCR, PCR-Southern blot hybridization, and field test indicated that NPTII and bar gene introduced into the genome of petuina plants were stably transmitted to their progenies, and conferred the plants resistance to herbicide, Basta.sta.