Seismic attribute analysis, a method of highlighting important information in seismic data, has been used in various fields. Recently, several studies have used seismic attributes to interpret seismic anomalies associated with subsurface gas. In this study, we applied seismic attribute analysis to seismic data acquired in Yeongil Bay to identify the subsurface gas distribution. Before applying seismic attributes to the Yeongil Bay seismic data, we selected promising seismic attributes and applied them to F3 Block seismic data to analyze the relation between the seismic attributes and seismic anomalies caused by subsurface gas. Since there are previous studies on the subsurface gas in the F3 Block, we could identify the characteristics of the seismic attributes based on the F3 Block seismic data. Then, we applied the selected seismic attributes to the Yeongil Bay seismic data to define the subsurface gas distribution. Through seismic attribute analysis, a three-dimensional gas distribution model of Yeongil Bay was generated, and this model can provide quantitative information on the subsurface geology of Yeongil Bay.