Abstract:The coat protein gene of tobacco mosaic virus strain OM have been combined with the 35S promoter and terminator of cauliflower mosaic virus as a chimeric gene. After insertion of this gene into the plasmid pGV1103neo containing a NPT I gene which can express in agrobacteria and a chimeric NPT II gene which can express in plant, this chimeraic coat protein gene have bcen inserted into the T-DNA region of a modified Ti plasmid pGV3850. The agrobacteria with this Ti plasmid containing the coat protein gene of tobacco mosaic virus is suitable to transform plants and to see if the expressed coat protein can delay or decrcase the symptom caused by tobacco mosaic virus in transgenic plant.