In order to enhance the disease resistant ability of apple，the plasmid encoding NPTⅡ gene，GUS gene，and β-1,3 glucanase gene was transferred into apple cultivars of Fuji and Gala via Agrobacterium tumefaciens mediated. Seventeen Gala and 11 Fuji transgenic lines succeeded in the Kanamycin resistant screen，GUS stain，and PCR analysis. From those，3 lines of each cultivar were chosen for Southern blot analysis，which confirmed that the exogenous genes had been integrated into the genome of the transgenic lines. Then，five lines of each cultivar were chosen for Semi-quantitative RT-PCR analysis. All the lines except one from Fuji cultivar showed the positive target bands. The bands varied in brightness and sharpness indicated the difference of the gene expression among the transgenic lines. The detached leaves from the lines were inoculated with the spores of Alternaria mali and incubated. Among 10 Gala lines and 7 Fuji lines tested，8 Gala lines and 2 Fuji lines showed disease resistance at certain extent，and the enhancing of the disease resistance related to the gene expression.