The Western Depression of Liaohe Rift is a typical half-graben depression. Controlled by step normal faults, two kinds of sedimentation models developed here, gentle and steep during Paleogene. After experiencing the three stages of structure-sedimentation evolution, namely, initial subsidence-rifting depression, spreading and re-depression, witch are characterized by proximal provenance and short transportation sistance. and coarse clastic fan-delta, sub-lacustrine fan sandstone reservoirs have developed. Having undergone compaction, cementation and dissolution processes. The reservoirs are manly in early diagenesis stage and late diagenesis stage A. Double controlled by sedimentation and diagenesis, the main pore types of sandstone reservoirs are intergranular overgowth pore. The pore losing by compaction are larger than the pore losing by  cementation. Several secondary porosity development zones have been developed in sandstone reservoirs vertically. In the aspect of sandstone reservoir quality and petroliferous property, the fan-delta reservoirs are the best compared to the other reservoirs, and they are the most important hydrocarbon reservoirs in this depression. This research indicates that the deep exploration has great hydrocarbon potential. The oil and gas exploration directions have been pointed out in this paper also.