The Yunnan Province of China is one of the centers of diversity of Asian cultivated rice (Oryza sativa L.). Its rice genetic resources are of great importance worldwide in terms of diversity of varieties abundance and complexity of types. This paper places emphasis on the genetic resources utilized for breeding programs in Yunnan including the collection of germplasm and evaluation of characters as well as investigations on wild and cultivated species. Achievements have been obtained in breeding for high yield, cold tolerance, blast resistance or quality and all the improved varieties show characteristics suitable for highland and standard agriculture. Many materials which include valuable germplasm for breeding, display the following characteristics : ultra-large ear weight, high tolerance to cold, high resistance to diseases (upland rice) and high quality comparable to that of Run-rice (indica rice). However, since most of the varieties exhibit a tall plant height, a week tillering ability and a disorganized arrangement of leaves, improvement of the plant type is the first priority in rice breeding. Varieties successfully improved by hybridization are mainly derived from materials from Japan and Taiwan for keng (japonica) rice or from IR lines of hsien (indica) rice used as parents. Intermediate types are less selected as parents because breeders world like to use the lines with a superior plant type. The abundant rice resources in Yunnan are not fully exploited and utilized and breeders should pay attention to this problem in further studies.