Abstract: Starting with analyzing the exploration status of oil-gas reservoirs in western sags of Liaohe Depression, it is thought that the western sags have entered into high mature stage of exploration,after the origins ofvarious-type lithologic reservoirs in western sags were studied, but there is still a considerable potentialfor lithologic oil reservoirs to explore.On the basis of summarizing on distributioncharacteristics of variouslithologic reservoirs, it is pointedout that, the majorfuture exploration fields should be turned to lithologic reservoirexploration fromstructural reservoir exploration,and the next exploration targets will focus on the following areas, i.e.Yuanyanggou-Qijia area, the downthrough side of Taizhuang-Dawa fault, Dongying Formation in Qingshui sag,Xinglongtai-Maquanzi burial hills belt and burial hills belt in western slope

Key words: Liaohe Depression;western sag;transitional zonebetween sag and slope, lithologic oil-gas reservoir