Abstract: Sedimentary facies, sandbody distribution and their control over oil and gas accumulation in the second and third members of the Yaojia Formation in Haituozi area, the Songliao Basin were poorly understood during the process of exploration. In order to solve these problems, the authors deliberately studied sedimentary microfacies, the types of main sandbodies and their distribution in this area by using modern sedimentary and sequence stratigraphy and on the basis of core, logging, seismic and related experimental data. Also, the evolution of sedimentary facies and their control over oil and gas accumulation was summarized, and the pinch out position of sandbeds and advantageous reservior zones were pointed out. All these provided technical supports to looking for blind reservoirs in this area.