The Chang 7 oil formation in the Ordos Basin is an important reservoir for tight oil，but its provenance directions and source area lithology during the depositional period remain controversial，and the classification of depositional systems requires further refinement. Based on previous research and newly supplemented geological data，the provenance directions and source area lithology of the Chang 7 oil layer group in the Yishan Slope of the Ordos Basin were systematically investigated through the analysis of light and heavy mineral assemblages，paleocurrent directions，and rare earth element distribution patterns. Additionally，using field outcrop observations，core analysis，thin-section examination，and well-log data，the depositional system types and their distribution patterns were refined. The results reveal that the Chang 7 oil layer group in the Yishan Slope is supplied by multiple provenance directions，including the southwestern and southern source areas （Longxi Palaeoland and Qin-Qi Folded Orogenic Belt，with lithology dominated by mixed granites），northeastern and eastern source areas （Guyinshan and Daqing Mountain，with lithology dominated by Archaean and early Paleoproterozoic metamorphic rocks），and northwestern source areas （Alashan Palaeoland，with lithology dominated by Archaean migmatites）. The depositional systems are primarily lacustrine and deltaic，including shoreface-littoral lakes，deep lakes，braided river deltas，and meandering river deltas. The deep lake facies are widely distributed in the southeastern Huangling-Fu County-Ganquan area，central Zhidan-Baibao area，northwestern Dingbian-Majiatan area，western Huanxian area，southwestern Zhenyuan-Jingchuan area，and southern Xunyi area. Shoreface-littoral lake deposits are distributed in a belt-like pattern around the deep lake areas. Braided river deltas are mainly located in the southwestern Huanxian，Zhenyuan-Qingyang，and Xunyi-Heshui areas，while meandering river deltas have a broader distribution，covering the northeastern and eastern areas，including Yanchi-Dingbian，Anbian-Wuqi，Zhijing，Yulin，Anse，Yanan，and Fu County regions. The research results establish a critical foundation for reservoir prediction and hydrocarbon exploration in the Chang 7 tight oil reservoir system of the Ordos Basin.