The wild Pyrus plants belong to the deciduous woody plants in Rosaceae family. Most are cultivated for fruit productions, but some for ornamental plants. There are 5 Pyrus species including Pyrus ussuriensis and 8 varieties cultivated in Korea. In Korea, these plants are populated near villages or on the hills, and they are easily propagated since their fruit are very juicy and quite big in size. Plant breeding to get improved cultivars is not difficult because the Pyrus plants are easy to cross breeding among its genus. Because not only this reason but there have been shown lots of variation in wild groups, the Pyrus plants inhabited in Korea are excellent deciduous woody plants and favorable fruit trees to develop ornamental plants. It is necessary to develop many kinds of fruit trees and ornamental trees containing genetically different character, so that it will be satisfied for many different people's taste and demands. Collecting lots of wild plant resource with diverse genes is necessary for plant breeding.