The Hohxil region in the northern Qinghai-Tibet Plateau is occupied by numerous plateau lakes,which have long been inferred as being tectonic products.However,so far little evidence has been found to support this tentative inference.Field survey and morphotectonic analysis of TM satellite images in the eastern segment of the Hohxil region revealed that Kusai Lake and Yelusu Lake are S- shaped pull-apart basins,which were dominated by left strike-slip master faults trending WNW-ESE. The pull-apart distances of the two lakes are analyzed to be<15-20 km and 15 km respectively.Based on studies of the faulting rate,the initiation ages of the pull-apart basins are suggested to be approximately in the Early Pleistocene.The pull-apart basin tectonics is further regarded as a common mechanism for the widely distributed large lake basins in the northern Qinghai-Tibet Plateau.Regional distribution of these pull-apart basins and their substantial intra-block slip suggest that a sinistral shear stress,which is independent of the distinguished strike-slip faults,has been imposed on across the northern Qinghai-Tibet Plateau.Thus,the intra-block slip may be an important expression of the eastward extrusion of the Plateau crustal material in accommodating the ongoing continent-continent convergence between India and Eurasia.The revelation of pull-apart tectonics within the Plateau hinterland provides field evidence and a possible style of deformation for the newly proposed continuous deformation by the global positioning system (GPS) measurement across the northern Qinghai-Tibet Plateau.A model,with respect to systematic tectonic landform development,for pull- apart basins is finally proposed. The Hohxil region in the northern Qinghai-Tibet Plateau is occupied by numerous plateau lakes, which have long been inferred as being tectonic products. However so little little evidence has been found to support this tentative inference. Field survey and morphotectonic analysis of TM satellite images in the eastern segment of the Hohxil region revealed that Kusai Lake and Yelusu Lake are S-shaped pull-apart basins, which were dominated by left strike-slip master faults trending WNW-ESE. The pull-apart distances of the two lakes are analyzed to be <15-20 km and 15 km respectively. Based on studies of the faulting rate, the initiation ages of the pull-apart basins are suggested to be approximately in the Early Pleistocene. The pull-apart basin tectonics is further rated as a common mechanism for the widely distributed large lake basins in the northern Qinghai-Tibet Plateau. Regional distribution of these pull-apart basins and their substantial intra-block slip suggest that a sinistral shear str ess, which is independent of the distinguished strike-slip faults, has been imposed on across the northern Qinghai-Tibet Plateau. Touhus, the intra-block slip may be an important expression of the eastward extrusion of the Plateau crustal material in accommodating the ongoing continent-continent convergence between India and Eurasia. The revelation of pull-apart tectonics within the Plateau hinterland provides field evidence and a possible style of deformation for the newly proposed continuous deformation by the global positioning system (GPS) measurement across the northern Qinghai-Tibet Plateau. A model, with respect to systematic tectonic landform development, for pull-apart basins is finally proposed.