Abstract: Volcanic eruption facies and flooding facies are extensively developed in the Sihetun area,west Liaoning.Such voluminous and rapid volcanic activities in Phanerozoic have commonly been thought to be a cause for zoobio cenose extinction.The all uvial-fluvial,shore-shallow lacustrine,semi-deep and deep lacustrine facies were developed during volcanic dormancies,which provide evidence to study the influences of volcanism on sedimentary environment.The influences include: infilling of both volcanic and weat hering materials; burial and control by multiphased volcanic activities and upwar dchanges of volcanic-sedimentary facies associations; the Yixianian volcanic activities initiated crustal uplift and tectonot-opographic changes,which in turn affect draining modes; the biota experiencing volcanism influences can be evident for climate change.