Abstract: Liaodong uplift is located in the northern Bohai part of Tan-Lu fault zone, adjacent to the west of Liaozhong sag. The tectonic evolution of Liaodong uplift is extremely complicated as influenced by the double dynamic source and multi-stage episodic activities of Tan-Lu fault zone since the Cenozoic. In particular, the formation period of Liaodong uplift has still not been determined. Aiming at this issue, based on new theories and techniques in tectonic geology (fault-related fold theory and sandbox simulation experiment), this study proposes that the strike-slip inversion structure of Liaodong uplift had begun to develop from the depositional stage of the third member of Dongying Formation (30.3 Ma), which is demonstrated in terms of the marginal fracture system evolution, stratigraphic distribution, axial surface inflection point of normal drag folds, unconformity distribution as well as slump and sublacustrine fans. Further, the existence and collapse of the "ancient Liaozhong sag" is first presented herein through tectonic evolution analysis, based on which it is explored using sandbox simulation experiment that the partial and intense differential settlement caused by oblique pull-apart and strike-slip activities is contributed to the "relative uplift" of Liaodong.