The purpose of this article discusses the phenomenon of kaserepan in gamelan koromong art performances which is located in the area of Cikubang Village Sumedang Regency of West Java. This phenomenon occurs in a ritual ceremony held to honor Dewi Sri. The event that was performed annual on 14 Maulud is thick with a mystical atmosphere, where in the process of calling the ancestral spirits which is believed with the presence of Dewi Sri. These spirits will enter into the ritual dancers who are following the show. This phenomenon is called by the term kaserepan which is the entry of ancestral spirits to the ritual dancers in the performing of gamelan koromong art.