Based on field observations in Chongqing, Hubei, Jiangxi, Yunnan, Zhejiang etc. provinces, and comprehensive study on more than 7,000 specimens including 161 type specimens from 20 herbaria, referring to the former results and geographical data, the variation scope of all the morphological characters in Elaeagnus from Mainland China were carefully analysed and discussed. Some reliable diagnostic characters were found, which played an important role in resolving the problems of species delimitations. Then, the classifications of Elaeagnus were primarily researched. The main results were summarized as follows: First, all the morphological characters in Elaeagnus from Mainland China were carefully analysed and discussed. And their taxonomic significance was re-evaluated. The results show that abaxial hairs of leaves, shapes of calyx tube, nature of drupe and fruiting pedicel etc. were constant within species and thus they are good characters for classification. Second, based on above results, taxonomic notes on Elaeagnus in mainland China were made. Thirteen species names and six varieties names were regarded as new synonyms, viz. Elaeagnus angustata (Rehd.) C. Y. Chang var. songmingensis W. K. Hu & H. F. Chow ex C. Y. Chang was regarded as a new synonym of E. angustata (Rehd.) C. Y. Chang, E. angustifolia L. var. orientalis (L.) Kuntze as a new synonym of E. angustifolia L., E. bockii Diels var. muliensis C. Y. Chang as a new synonym of E. bockii Diels, E. difficilis Servettaz var. brevistyla W. K. Hu & H. F. Chow as a new synonym of E. difficilis Servettaz, E. geniculata D. Fang as a new synonym of E. gonyanthes Bentham, E. griffithii Servettaz var. multiflora C. Y. Chang and E. griffithii Servettaz var. pauciflora C. Y. Chang as new synonyms of E. loureiroi Champion ex Bentham, E. heterophylla D. Fang & D. R. Liang and E. luoxiangensis C. Y. Chang as new synonyms of E. glabra Thunb., E. hunanensis C. J. Qi & Q. Z. Lin as a new synonym of E. lanceolata Servettaz subsp. grandifolia Serv., E. jiangxiensis C. Y. Chang as a new synonym of E. grijsii Hance, E. longiloba C. Y. Chang, E. retrostyla C. Y. Chang and E. xingwenensis C. Y. Chang as new synonyms of E. delavayi Lecomte, E. micrantha C. Y. Chang as a new synonym of E. argyi Léveillé, E. multiflora Thunb. var. siphonantha (Nakai) C. Y. Chang as a new synonym of E. multiflora Thunb., E. obovatifolia D. Fang as a new synonym of E. pingnanensis C. Y. Chang, E. obtusa C. Y. Chang as a new synonym of E. pungens Thunb., E. xichouensis C. Y. Chang and E. xizangensis C. Y. Chang as new synonyms of E. viridis Servettaz. Third, two species E. nanchuanensis C. Y. Chang and E. wushensis C. Y. Chang were reinstated as E. magna (Servettaz) Rehder var. nanchuanensis (C. Y. Chang) M. Sun & Q. Lin and E. magna (Servettaz) Rehder var. wushanensis (C. Y. Chang) M. Sun & Q. Lin, respectively. Fourth, after carefully study on the type specimens, lectotypes for five names, viz. E. luoxiangensis C. Y . Chang, E. micrantha C. Y . Chang, E. pilostyla C. Y . Chang, E. xichouensis C. Y . Chang and E. xingwenensis C. Y. Chang, were here designated. Last, as a conclusion, thirty-six species, one subspecies and five varieties were recognized in this genus in mainland China. In addition, descriptions, geographical maps and keys to the taxa of Elaeagnus were given. And also, the patterns of floristic division in China of Elaeagnus were analyzed and discussed.