Objective: A series of folds and thrust faults was formed in the central part of Lanping—Simao Basin that constituted of a reversed Sshaped structure. The quantitative analysis on the way and process of the Lanping—Simao crust evolution has an important geological implication, because the crustal surface deformation and tectonic evolution are closely related to the tectonic evolution of the southeastern Tibetan Plateau. Based on paleomagnetic studies of the Early Cretaceous red beds and the tectonic evolution process of regional active faults in the Lanping—Simao basin, the paper discusses the originated model of the reversed Sshaped structure in the central Lanping—Simao Terrane. Methods:There are 211 representative paleomagnetic samples picked out from the Early Cretaceous red beds at four sections in Nanjian area of the central part of the Lanping—Simao basin, and then the rock magnetic and paleomagnetic studies were carried out. Results: The characteristic remnant magnetization (ChRM) directions obtained from two sections at Niujie area are Ds= 244.7°，Is = -47.3°，Ks = 31.6，α95 = 16.6 (K1j1) in the LNa section, and Ds = 245.4°，Is = -46.4°，Ks = 52.2，α95 = 9.4 (K1n2) in the LNb section, respectively. A fold test was performed on the two sections and was positive at the 99% confidence level (McFadden, 1990). The tilt corrected site—mean directions from two sections at the Xiaowanzhen area are Ds = 244.9°，Is = -40.2°，Ks = 1067.5，α95 = 2.3 (K1j1) in the NXa section, and Ds = 182.6°, Is = -42.1°, Ks = 335.2, α95 = 3.7 (K1j2) in the NXb section, where the two sections are located in different limbs of the folds Conclusion: We propose the originated model of the reversed Sshaped structure in the central Lanping—Simao Terrane, showing that the formation, its evolution and differential rotations of reversed Sshaped structure were controlled by the extrusion effect of different small crustal blocks in the southeastern Tibetan Plateau during the India/Eurasia collision since the early Tertiary, and the response of compression on the resistance of the Lincang granite batholith.