This study examined the characteristics of costumes worn at Halloween parties, a form of cultural entertainment commonly seen in the U.S. The Halloween party culture involves children and adolescents wearing costumes, decorating their bodies, and mimicking famous characters. Furthermore, the types and motifs of Halloween costumes have become a means of expressing individuality. This study conducted empirical research on how such motifs were reflected in modern Halloween party-wear in order to provide basic data regarding the development and design of Halloween costumes and the formation of the related entertainment culture. This study researched the shape of costumes and the type of traditional motif presented in these costumes, as well as analyzed the symbolic meaning of each motif. The research process was as follows. First, this study investigated the origin and evolution of Halloween by researching precedent studies, books, and internet data. Second, this study extracted the types of traditional Halloween motifs by analyzing the characteristics and symbols of Halloween costumes commonly presented in such materials. After collecting 547 Halloween-related images from U.S. and Korean Internet websites, this study sorted and analyzed images that could represent traditional Halloween motifs. According to the results, representative traditional Halloween motifs included black cats, white rabbits, tridents, scarecrows, skull and bones, ghosts, witches, vampires, bats, werewolves, and jack-o-lanterns(pumpkins, etc.). The sentiments for such traditional Halloween motifs changed according to era and race. The symbolic meaning would continuously change - from positive to negative and vice versa - to reflect various socio-cultural phenomena. The results of this study are expected to be used as basic data for developing Halloween costume designs and the related entertainment culture.