Abstract: The Yanan sag of Qiongdongnan Basin is located in pressure transition zone, and it is characterized by complicated reservoir-forming conditions and oil & gas accumulation rules, deeply buried targets, great lateral variation of reservoir, and strong physical heterogeneity. On the basis of fully study of reservoir characteristics and selecting the technology for reservoir prediction and oil & gas detection, the spatial distribution of lithologic reservoir of Sanya Formation is described, the distributed areas of effective reservoir are confirmed, and favorable zone and targets for oil and gas reservoir exploration are identified, by using the acoustic impedance inversion technology, the spectral imaging analysis technology, the technology for analysis of attenuation by absorption and other technologies.