Abstract: Baolongshan coalfield is taken as an example to dissertate the method and reason of finding coal under red-beds from Songliao basin.Based on the data of seismic and drilling prospecting,forming mechanism of the basin,character and evolution of the basin margin fault,the time and space variation of coal accumulation,allocation of sedimentary environment and facies,and coaly coefficient are discussed systematically.The research indicates that the tracing contrast of seismic cross-section,the continuity and super-coverage relationship of isochronous interface and its morphological change,and the internal structure of reflecting wave,are especially helpful to determine the framework of strata,to analyza the formation and development of fault depression,to discuss the filling evolution process and its control action.Based on the above study,the western slope of Songliao basin,including several sub-basins such as Daolaodu-Gaoliban,Zhenlai-Xinglongshan,Juliuhe,Zhanyu,and Xiboyinzi-Baolongshan,is speculated to be an important exploration targetarea of coal resources.