Abstract: Elamena (Decapoda: Brachyura: Hymenosomatidae) is a group of small crabs which now consists of 27 species occurring mainly in the Indo-West Pacific region. Elamena rostrata was reported with only one female specimen, lacking of characteristics of male individual which has not been reported so far, though, it is always extremely important for identifying crabs. Fortunately, two specimens including one male which was the first specimen of this species in the world collected from Xiangshan Bay, Zhejiang China, were identified as Elamena rostrata. The main diagnostic characteristic of male Elamena rostrataare as follows: carapace subtriangular, longer than broad; rostrum long and triangular with distinct keel on ventral surface; pterygostomian region with a small triangular lobe; Milne Edwards’ openings not fused for more than half their length; ambulatory legs very long and slender, dactylus of which with 2 subterminal teeth and dense setae on posterior margin; abdomen 5-segemented(including telson), telson triangular; G1 with 2 short setae on dorsal edge and 7 longer setae on ventral edge.