The Domi Basin in the South Sea of Korea is located between the Jeju Basin and Ulleung Basins, and is characterized by several sediment sags that are interested to have formed by crustal extension. This paper aims to derive an optimized seismic data processing procedure which helps stratigraphic interpretation of the Domi Basin. In particular, our data processing flow incorporated horizon velocity analysis (HVA) and surface-relative wave equation multiple rejection (SRWEMR) to improve the quality of stack section by enhancing the continuity of reflection events and suppressing peg-leg multiples respectively. As a result of processing procedures in this study, unconformities were recognized in the stack section that defines the early and middle Miocene, Eocene-Oligocene sequences. In addition, the overall quality of the stack section was increased as essential data to investigate the evolution of the basin. The suppression of multiple resulted in the identification of the Cretaceous basement. The data processing scheme evaluated through this study is expected to improve the standardization of processing sequences for seismic data from the Domi and adjacent Sora and north-Sora Basins.