Plant expression vectors, pBCry3A and pBC₃Vhb, containing cry3A gene and both cry3A and vhb genes respectively, were constructed. Potato leaf-explants were transformed via Agrobacterium harboring pBCry3A or pBC₃Vhb respectively. Results from PCR and genomic DNA Southern blotting analysis indicate that cry3A or cry3A+vhb gene have been integrated into the genome of the transformed potato lines with 1～3 copies at least for cry3A gene. The transgenes were stable and expressed even after three successive clonic propagations. Results from ELISA analysis showed that the highest expression level of Cry3A protein reached 0.1% of total leaf soluble protein among cry3A transgenic plants, while that of the cry3A+vhb transgenic plant reached 0.065%. RT-PCR analysis of vhb mRNA and waterlogging test demonstrated that the transgenic potato plants transformed with cry3A+vhb genes expressed vhb gene at least at transcription level and showed obvious higher tolerance against low-oxygen stress. These results together with that of the ELISA for Cry3A indicate that this kind of transgenic plants could be valuble in application for insect resistance and waterlogging tolerance.