Recent molecular phylogeny of deer revealed that the characters of antlers previously focused on are homoplasious, and antlers tend to be considered problematic for classification. However, we think antlers are important tools and reconsidered and analysed the characters and structures to use them for classification. This study developed a method to describe the branching structure of antlers by using antler grooves, which are formed on the antlers by growth, and then projecting the position of the branching directions of tines on the burr circumference. By making diagrams, comparing the branching structure interspecifically, homologous elements (tines, beams, and processes) of the antlers of 25 species of 16 genera were determined. Subsequently, ancestral state reconstruction was performed on the fixed molecular phylogenetic tree. It was revealed that Capreolinae and Cervini gained respective three-pointed antlers independently, and their subclades gained synapomorphous tines. We found new homologous and synapomorphous characters, as the antler of Eld's deer, which has been classified in Rucervus, is structurally close to that of Elaphurus rather than that of Rucervus, consistent with molecular phylogeny. The methods of this study will contribute to the understanding of the branching structure and phylogeny of fossil species and uncover the evolutionary history of Cervidae. Antlers are a symbolic part of cervids. Species identification and taxonomy of fossil species are mostly based on antlers 1-7 , owing to their frequent production as fossils and morphological diversity. Recent molecular phylogeny 8-12 revealed that the characters of the antler that have been conventionally focused are considerably homoplasious 8. There is a view that antlers are problematic as morphological characters for classification 12 , and attempts to combine antlers and phylogeny are currently inactive. In recent phylogenetic analyses using morphological characters 12,13 , the number of antler characters is not large. However, antlers are important characters of Cervidae, and we consider that they should be the main tool for the classification of Cervidae. We think that the phylogeny of antlers reached its limits because the point of antler characters that have been focused upon are a problem. In particular, the branching structure of the antlers, that is, the homology of tines (as skeletal elements), is considered to be indispensable for classification, but there is still no common view. Widely accepted identification characters of antler homology, or at least those in which the same terminologies are used, are the brow tine and beam of many species 14-29 and trez tine (or tres tine or tray tine) and bez tine (or bay tine) of Cervus and Dama 14,19,22,24,28,30. Especially for the distal tines, there has been little identification of homology and, concomitantly, the terminologies of the tines have been unconsolidated or absent, which has caused confusion. Attempts to identify the homology of tines have been ongoing since before the 1900...