Abstract: The fruits of Dendyobium devornianum are used as the research materials. On the basis of seed in virto and organ in virto culture, using in virto seedings and polyploid technology to breed the polyploid plants in short time, the result of preliminary study show that the polyploid Dendybium plants have taken great changes on the shape, the diameter of stoma and the number of chromosome, which provides a new method on the orchid breeding study.