Indonesia is known for its variety of tradition. The ritual of Merti Bumi Tunggularum is among the important traditions which has not been explored in studies. This study explores the origin of Merti Bumi tradition, especially related to the community values of religious harmony. This study employs a qualitative-descriptive approach. The results of this study highlight that: (1) The tradition of Merti Bumi Tunggularum is referred to the respected figure of Kyai Tunggul Wulung, in which his death is commemorated through the ritual of annual Haul held in the community in the month of Sapar 21st. This annual haul has been developed into various traditions, including the Carnival of the Merti Bumi and some other related ceremonies. (2) The ritual of Merti Bumi reflects community’s value of religious harmony as it involves tolerance, equality and mutual cooperation among people from various religious backgrounds in the society. [Indonesia dikenal dengan keragaman tradisinya. Ritual Merti Bumi Tunggularum adalah salah satu tradisi berharga yang belum dieksplorasi dalam studi ilmiah. Penelitian ini menelusuri awal mula tradisi Merti Bumi, terutama yang beekenaan dengan nilai-nilai kerukunan umat beragama. Penelitian ini menggunakan pendekatan kualitatif-deskriptif. Hasil dari penelitian ini mengemukakan bahwa: (1) Tradisi Merti Bumi Tunggularum merunut pada tokoh Kyai Tunggul Wulung yang sangat dihormati, yang kematiannya diperingati melalui ritual Haul tahunan yang diadakan pada bulan Sapar ke 21. Peringatan ini telah dikembangkan menjadi berbagai tradisi, termasuk upacara Merti Bumi dan upacara lainnya yang berkaitan. (2) Ritual Merti Bumi mencerminkan nilai kerukunan beragama masyarakat karena memegang teguh toleransi, kesetaraan, dan gotong royong timbal balik pada semua lapisan masyarakat dengan berbagai latar belakang agama yang berbeda-beda.]