Abstract: Agrobacterium-mediated transformation system of Petunia hybrida was estabilished and optimized with P. hybrida leaf as the material. Antisense F3'H gene was transfored into Petunia by Agrobacterium-mediated transformation system. The resistant plants were all positive plants by PCR detection, which indicated antisense F3'H gene had been integrated into Petunia genome. Compared with non transgenic plants, F3'H gene expression in the positive plants detected by semi-quantitative RT-PCR was abate, which showed that the import of antisense F3'H gene inhibited the expression of endogenous genes.