Research on the aesthetic acculturation of the ornamental Bungong Baiturrahman mosque uses the theoretical framework method as an analytical scalpel; acculturation theory leads to Koentjaraningrat's thoughts, aesthetic theory, and Charles Sanders Pierce's semiotic theory understand communication evidence of signs from a reality. The analysis of the aesthetic ornamental bungong on the cross between European and Middle Eastern cultures traces the process of acculturation that affects the Baiturrahman bungong decorative mosque based on the communication literature of icon, index, and symbol indicators. The shape and meaning of ornamental bungong are based on a semiotic representation of flora, nature, calligraphy and arabesque. The elements of flora consist of Bungong Meusingklet, Bungong Ban Keumang, Bungong Meulu and Pucok Rebong. The natural form consists of a bulen star, rante, puta taloe, si oen¸ cloud, and kande lamp. Calligraphy and arabesque forms consist of geometric elements and the pronunciation of Allah with the art form of calligraphy. The ornamental bungong has a philosophical meaning as local wisdom of cultural values in regulating the social life of the Acehnese people and also influences the reference to the shape of the ornamental bungong both in terms of architecture and the application of objects scattered throughout the archipelago.