Abstract: A new species of the genus Armeniaca Scop. of Rosaceae, A.cathayana D. L. Fu, B. R. Li et J. H. Li, sp. nov., was described in this paper. The species appears to be similar to A.vulgaris Lam. and A.sibirica (L.) Lam., but it has some particular characteristics which can be distinguished from A.vulgaris Lam., A.sibirica(L.) Lam. and other species of the genus. The main distinguishing features are that the leaf blade pubescent sparsely on both surfaces, the margin serrate and biserrate, and entire at base; the petiole not glandular; the inflorescence 1-3-flowered; the ovary with white villous densely; the endocarp triangle ovoid with 5~7 longitudinal sharp ridges on ventral suture and 1 longitudinal shallow groove on dorsal suture; the seed large and compressed, and the kernel friable and not bitter. The species was found and collected on July 11, 2008 in Zhuolu County, Hebei Province of China by Da-li Fu. The holotype is kept at Chinese Academy of Forestry (CAF), No.2008071101.

Key words: Rosaceae, Armeniaca Scop., Armeniaca cathayana D. L. Fu, B. R. Li et J. H. Li, New species