There is a vast ditinction in the number structure between the Loropetalum chinense and the Loropetalum chinense var. rubrum. The 4 number character is about 96.2% in Loropetalum chinense (the flower petal, stamen, degenerated stamen and the sepal are also 4). The 4 number character is about 50% in wild Loropetalum chinense var. rubrum. The cultivated Loropetalun chinense var. rubrum's flower is always 5. There is a distinction in the number genetic structure of flower in diferent kind of variety. The law of totality variation is: present cultivated variety shuangmianhong type 5 number genetic flower>midterm cultivated variety touguhong type>early stage cultivated variety nenyehong type. The origin, the evolutionary history and the prospect of breeding of the Loropetalum chinense var. rubrum are discussed based on the number variation of the flower structure.