Hailar Basin is a fault-depressed basin formed on Variscan folded basement. The Zhalainuoer Group in the basin could be divided into 4 sedimentary assemblages: 1. basal coarse clastic section; 2. lacustrine coarse c1astic section; 3. lacustrine fine clastic section;4. coal-bearing clastic section. They constituted a relatively complete basin-filling sequence. The sandstones in low maturity formed in inland deep fault-depressed basin and derived from active continent margin or island arc. The reservoir models can be classified as nearshore subaqueous fans

turbidity sandbodies and lake shore sandbodies.