Abstract: 1. Investigation，collection and conservation of the Eriobotrya germplasm. After the investigation of Eriobotrya species distributed in the 14 provinces of China，we confirmed that totally there were 20 wild Eriobotrya species which mainly distributed in Yunnan and other several provinces. Other 6 Eriobotrya species were found in several Southeast Asia countries such as Vietnam，Laos，Burma and Thailand. All the mentioned 26 Eriobotrya species were collected and ex situ conserved. 2. Categorization，identification and evaluation of the Eriobotrya germplasm. Based on newly finding，1 new species was published（E. fulvicoma Chun & Liao），1 species was revised（E. × dadunensis H. Z. Zhang & W. B. Liao），1 species was redescribed（E. kwangsiensis Chun），new distributions of 4 species were reported，and illustration of the 26 Eriobotrya species was published. Phylogenetic analyses indicated that species with smaller leaf and less stigma number（2，3 or 4） such as E. henryi Nakai，E. seguinii Card and E. angustissima Hook. f. are the basal taxa of Eriobotrya species，while species with bigger leaf and 5 stigmas such as cultivated loquat（Eriobotrya japonica Lindl.），E. malipoensis Kuan and E. elliptica Lindl. are grouped together. More than 50 traits of the 26 Eriobotrya species were characterized comprehensively and the traits with potential economic values，such as the hybridization compatibility，the karyotype，contents of the triterpene acids，developmental characters of the root，resistance to the loquat leaf spot，flowering habit and the fruit quality，were further evaluated in some species. 3. Utilization research of the Eriobotrya germplasm. Several species or their interspecific hybrids were identified as the rootstocks for cultivated loquat，including E. fragrans Champ，E. salwinensis Hand-Mazz and E. elliptica Lindl. Content detection of the triterpene acids with main medical compositions for production of antitussive，ursolic acid，for example，in the leaf indicated that several wild loquats，such as E. deflexa Nakai and E. fragrans Champ，showed a higher content level than that of the cultivated loquat. Furthermore，pathology analysis data showed that the ursolic acid and oleanolic acid extracted from leaf of E. fragrans Champ could not only inhibit the survival and proliferation of human lung cancer cell but also could induce its apoptosis. At the same time，hundreds of hybridization tests with interspecific crossing or intergenetic crossing were performed to reveal their cross-compatibility and transferable capacity of the valuable characters to the cultivated loquat.

Key words: Eriobotrya, wild species, germplasm resources, investigation, conservation, categorization, evaluation, utilization