Volcanic intercrystalline micropores mainly formed by recrystallization and dissolution develop widely in the Yingtai fault depression, southern Songliao Basin. According to the genesis and types of skeleton grains, volcanic intercrystalline micropores can be divided into three types, i.e. intercrystalline micropores of radial alkali feldspar, clay minerals and mixed minerals. Surface po- rosity analyses showed that due to the devitrification of matrix, the porosity of intercrystalline micropores in the spherulitic K-feld- spar region amounts to 5.2%, the porosity of intercrystalline micropores in the region of clay minerals and quartz-feldspar crystal- lites increases from 9.5% to 13.5%, the porosity of intercrystalline micropores in the region where partial feldspar alters to illite may increase to 6.5% ~ 10. 1%, while intergranular pores o{ pyroclastic rocks filled with illite can still retain a porosity of 22.3 % for intererystalline micropores. Combined with the exploration practice in the Yingtai fault depression, we suggested that volcanic rocks with rich intercrystalline micropores can serve as a favorable reservoir of natural gas.