Research Institute of Exploration and Development of Daqing Oilfield Company Ltd.，Daqing 163712，Heilongjiang，China

In order to find out the controlling factors of tight oil distribution in Gaotaizi oil layer of Qijia area， through the detailed study of sedimentary characteristics，the authors consider that the sediment facies is shallow delta in G3 － G4 oil layers， and developing delta plain， delta front and prodelta subfacies from north to south． Mul- tiple and small scale transgressions during the base level falling cause the multistage superposition between delta outer front and prodelta mud，and between the terminal of delta inner front and the mud of delta outer front，which provide the premise of source and storage match for inner source tight oil． Also，the authors analyze the control ac- tion of sediment facies on tight reservoir，high quality oil layers and the matching relationship between them，and point that there exist two kinds of tight oil reservoir in Qijia area，tight reservoir of distal bar in the terminal of delta inner front，tight reservoir of sheet sand in delta outer front． By comparing the superiority of the three conditions， the former is better in reservoir condition，hydrocarbon source rock condition and source storage matching，and is the most important tight oil reservoir type． Finally，it is pointed out the tight reservoir of distal bar in terminal of delta outer front is the most favorable microfacies in the next tight oil exploration in southern Qijia area．