The safety study of transgenic plants has an actual significance for creating new species and commercializing transgenic plants. Based on PCR and Southern blotting tests of transgene, the genetic stability of ipt gene in an advanced generation of transgenic rice plants was studied. Use a plate colony counting technique, the influence of ipt rice plants on bacteria number of rhizospheric soil was investigated. Molecular detection showed foreign ipt gene was stable genetic in the genome of T-8 transgenic rice with a single copy. The amounts of bacteria from the root soil of transgenic lines were distinct from non-transgenic controls during the tillering stage, heading stage and filling stage. Nevertheless, this variability was not significant during the growing season described above (P>0.05). These results reveal that T-8-ipt rice cannot affect the soil bacteria biomass during plants field-growth.