1. College of Earth Sciences��Jilin University��Changchun 130061��China; 2. Geophysical Exploration Institute of Heilongjiang Province��Harbin 150036��China

Through the observation of drilling cores��casting slides and scanning electron microscope��combined with intrusive mercury analysis test��the authors studied the pore structure characteristics of Shuangyang Formation reservoir in Luxiang fault depression of Yitong Basin. The results show that the main genetic type of reservoir is fan-delta sand body��partly is underwater fan sand body. The main sand pore type is secondary solution pore�� partly is primary intergranular pore��such as intragranular dissolution pore��primary intergranular pore and intergranular corrosion expansion pore. The reservoirs are low in porosity and permeability in general��with small pore throat��poor sorting and connectivity��on which��the second member of Shuangyang Formation is a little better than the third one��and the first one is the worst. The pore structure characteristics of Shuangyang Formation reservoir are mainly controlled by sand genetic types and diagenesis. In addition��particle size of rocks and tectonism also have some control actions to pore structure.