The section Moutan DC., tree peony is woody species in the genus Paeonia L. (Paeoniaceae). This taxon as an ornamental and medicinal plant is a traditional floricultural and popuJar flower in China from old times. The cultural history of tree peony in China is more than 2,00) years and in the present tree peony of over 800 cultivars is growing in China. In China, many researches about tree peony were accomplished in many fields: origin, distribution, breeding, taxonomy, physiology, reproduction and molecular biology, etc. Tree peony resource of China is the most abundant in the world and also it has the wide distribution range in China. Characteristics for culture and ornament of each cultivar group are very superior. Therefore to improve the genetic resource of 01ina tree peony using modem biotechnology and to enlarge its cultivation range is very important for development of newly improved varieties of tree peony.