Barentak dance is a dance by Boren (shaman) at Barumpe Mayang ritual ceremony in Dayak Simpakng tribe. Barentak is a foot-centered movement, which is a foot beat that follows the sound of accompaniment music and rayah (singing) sung by Pabayu. At the time of Barentak, Boretn was in a trance state to communicate with Duata or God, the spirits of ancestors to be present in Barumpe Mayang.Barentak is the centerpiece of the Barumpe Mayang. Barentak dance can not be separated in the running of the ritual. Barumpe Mayang is an ordination ceremony (level increase) performed by a Form to clean his body (mansiakng daging) by using pinang flowers (mayang). With this ordination it is expected that a Boretn will pass through renewal, be cleansed from disease, kept away from danger, given good luck, and given back strength (spiritual power).To solve research problems, structural functionalism theory is an anthropological perspective of Brown. This theory explores society as a social system, wherein the concept there is a concept of conditions of existence. The condition of existence is used as a process to achieve existence (something), which involves existence other than human beings to meet the needs of what is being done. If there is a missing structure and element, then there will be an imbalance, so Barumpe Mayang and Barentak dance cannot be done.The analogy is used to see the function of Barentak in the ceremony Barumpe Mayang. There are very supportive structures in it such as Barentak dance, motion, actors, accompaniment and poetry, offerings, makeup and clothing, floor patterns and so on. The structures, elements and parts are interconnected in the Barumpe Mayang ceremony, functioning, integrating, moving and operating in the unity of the system.Keywords: Barentak, Barumpe Mayang , Dayak Simpakng Tribe.