A thaumatin-like protein (Vatl-1) gene was cloned from a downy mildew (DM) resistant Chinese grape Vitis Amurensis cv. Zuoshan-1. Embryogenic culture of DM susceptible V. vinifera grape cv. Thompson Seedless was transformed using Agrobacterium transformation system. Transgenic lines of ‘Thompson Seedless’ carrying the Vatl-1 gene were verified by PCR analysis and southern hybridization. Inoculation experiment showed that tolerance to Plasmopara viticola was significantly increased in the transgenic grapevines as indicated by reduction of the infected area and zoospore numbers.