Eastern Indonesia has a complicated structure due to the collision of the Eurasian Plate, the Pacific Plate, the Indo-Australian Plate, and the Philippine Plate, creating an active seismic zone. The Banda - Seram segment of eastern Indonesia comprises subduction, rollback, detachment, slab tear, back-arc thrust, and the Banda volcanic arc. Sri Widiyantoro did a previous study in Eastern Indonesia utilizing seismic tomography methods to detect the upper mantle and the 180-degree curved transition zone under the Banda arc. In addition, Robert Hall and Spakman’s research of the upper mantle revealed the existence of a spoon-shaped mechanism in the band arc. Seismic tomography modeling, this research seeks to identify the tectonic features in Eastern Indonesia, such as partial melting, subduction, slab rips, back-arc thrust, Banda volcanic-arc, detachment, and faults, and to establish the most suitable mitigation strategies. This study uses earthquake data from the Meteorology Climatology Geophysics Agency database (BMKG) and the form of P waves. In this research from 1 January 2016 to 31 December 2020, with coordinates 1 - 12 LS and 120 - 135 BT, there were 81 recording stations and 11299 earthquake occurrences consisting of 175643 P waves and 27338 S waves. This work applies the FMTOMO method to a seismic tomographic model. This research indicates that high-velocity anomalies characterize subduction to a depth of 650 kilometers. On Buru Island, the high-velocity anomaly is diagnosed as a slab tear at a depth of more than 400 kilometers. This research identifies a 100-kilometer-deep Back-arc thrust on Wetar Island that produces shallow earthquakes. In addition, a low-velocity anomaly at a depth of 70 kilometers - 90 kilometers is characterized as partial melting due to its parallel location with the Banda volcanic arc. This study examines the connection between subduction and intense seismic and magmatic activity in Eastern Indonesia.