Abstract: Analysis on two types of Cretaceous volcanic rocks in the basement of the Yitong Basin and the extension of Quantou formation in the basin demonstrates that, the Yitong Basin was in the environment of denudation in Quantou Stage, and began to uplift together with Daheishan Mountain not later than that stage. The Quantou formation, which outcrops around the Yitong Basin, doesn't extend into the basin. Instead, it just distributes in some isolated small basins, such as the Shuanyang Basin, which has different evolution history to the Songliao Basin. The research on palaeocurrent also supports these views.