Abstract: Erlian basin is a rift lacustrine basin developed on the Hercynian geosyncline folded base in Early Cretaceous, is featured by simple sedimentary feature, depositional cycle, small lacustrine transgressive, dry climate, salinization lacustrine water and multi-andnear sources. On the basis of sequence stratigraphy analysis of Bayindulan sag, Wuliyasitai depression, Jiergalangtu sag and Saihantala sag, the integrated sequence stratigraphy section of lower Cretaceous has been established and the vertical sequence of sandbodies distribution in three-order sequence has been concluded. The main conclusions are as follows: Firstly, under the influence of three phases of episodic activities, three two-order sequences is composed of three depositional cycles and three regional unconformities; Secondly, under the control of structure activities such as fault-block activities and the influence of three-order climate cycles and source recharge , lower Cretaceous can be divided into six three-order sequence; Thirdly, because fault activities is weak and fault slope is gently , fan deltas exist in steep slopes in early and later stages and subaqueous fans exist and turbidite fans exist in troughs in middle stage. Fan deltas distributed in gently slopes and braided river deltas develop alternately in all stages.

Key words: sequence stratigraphy, vertical sequence of sandbodies distribution, Lower Cretaceous, Erlian basin