Abstract: In this paper,by analysis of reservoir characteristic,lithology,sedimental environment and geological feature of Putaohua oil layer in Fang 3 area Songfangtun oilfield,Songliao basin,the outhors disccuss reservoir characteristics and it's influence factors. Feldspathic sandstone and detritus sandstone are the main type of reservoir which's lithology has siltstone,fine sandstone etc. and which's cementation types have mainly contact-regenesis,porosity-contact,intermix etc.The sandstone's cementation matter are mainly mud,carbonate etc.The reservoir feature belongs to medium-low porosity and permeability.The sedimental environment and the storage characteristic is main controlling factors of the reservoir charateristic.In the underwater diffluence riverway and the diffluence riverway,sandstone's porosity and permeability is best and in the delta front and the estuarine dam,it is lower.