Abstract: Five volcanic facies and fifteen subfacies are identified in Yingcheng Formation by using the data of cores and cuts of 36 wells in the Songliao Basin. The distribution of volcanic rocks is controlled by deep-seated faults. The volcanic rocks near the deep faults are thicker than that far from deep faults. The crater is controlled by the bypass faults. The facies’ cycle of volcanic in the Songliao Basin has the following characters. The vertical facies’ cycle of volcanic near deep faults is effusive facies-effusive facies-volcanic vent facies or invading facies from lower to upper, while far from deep faults’ is effusive facies-extrusive facies-effusive facies or volcanic sedimentary facies. The horizontal facies’ rhyme is volcanic vent facies/invading facies-effusive facies-extrusive facies-volcanic sedimentary facies. The cha-racters of effusive facies are matting like overlap or mound shape, middle-lower amplitude, middling frequency, middle-bad continuum reflection, and intermittently continuum wave like reflection, which are 6～10 km wide and 200～400 m thick. The characters of extrusive facies is wedge or lentoid figure with middle-high amplitude, middle-low frequency, bad-middle continuum reflection, which are 6～8 km wide and 100～200m thick. The characters of volcanic vent facies and invading facies are steep mound shape with middle-high amplitude, low frequency, disorder reflection, only occurred near the crater, which are 2 km wide and 100～200 m thick. The character of volcanic-sedimentary facies is filling structure, middle-high amplitude, middle frequency and good continuum reflection, distributed in bottomland, which are 4～7 km wide and 50～150 m thick.

Key words: Songliao Basin, Yingcheng Formation of lower Cretaceous, volcanic facies, geologic-seismic characters, lithofacies model