Abstract: The tight sandy conglomerate reservoir in Baikouquan formation of Wellblock Fengnan, Junggar basin is characterized by various types of rocks, large range of grain size and severe heterogeneity, all of which have significant impacts on reservoir development effect. On the basis of the reference on national standard (GB/T 17412.2-1998) Classification and Nomenclature Schemes of Sedimentary Rocks, the rocks in Baikouquan formation can be classified as mudstone, moderate-fine sandstone, coarse sandstone, fine conglomerate, small pebble conglomerate, large pebble conglomerate and coarse conglomerate. The analysis on lithological and petrologic features of different rocks shows that there are differences in sedimentary environment, grain size, matrix content, physical property and pore structure among different lithologies. Coarse sandstone, fine conglomerate and small pebble conglomerate are dominant reservoir lithologies with the secondary of large pebble conglomerate. Dry layer or non-reservoir is mainly composed of mudstone, moderate-fine sandstone and coarse conglomerate. Based on lithological and petrologic features and their logging responses, interval transit time-deep lateral resistivity cross plot chart are established and a combined identification method of -ND and the plot is developed. The lithology obtained from logging identification matches well with that from cores, which could be widely used in the study area