The South Tien-Shan (STS) belt, in Central Asia, is one of the largest intracontinental orogens. It results from the reactivation of Paleozoic structures inherited from the Central Asia Orogenic Belt (CAOB) building. Understanding the current tectonics of STS requires the knowledge of the Paleozoic history which is, however, still debated. As the Kyrgyz part of STS has been less studied than the Chinese one, this thesis aims to provide a detailed study of the Kyrgyz STS. Studying metamorphic ranges along the STS suture allows constraining the subduction history. A pluri-disciplinary approach was used, firstly based on field observations, then on thermobarometric studies combining X-ray micro-mapping and thermodynamic modeling and finally on geochronological studies.Results show that the Talas-Fergana fault, which is a 2000 km long active fault, was an important discontinuity from Upper Carboniferous times as it separated two areas with distinct geodynamic evolutions. To the west, a north-dipping subduction of the Turkestan Ocean led to the development of an important magmatic arc. Around ca. 301 Ma, the collision of Kazakhstan and Alai blocks resulted in crustal thickening and nappe stacking. To the east, a south-dipping subduction is suggested by south dipping structures exhibiting both oceanic and continental high-pressures units exhumed in a lower-grade paleo-accretionnary prism along top-to-the-north thrusts and top-to-the-south detachments. The continental high-pressure unit was exhumed at ca. 320-330 Ma just after the Turkestan Ocean closure. During Permian times, a first reactivation phase was associated to transpressive tectonics and intense magmatism. At the southern boundary of STS, interactions between transpressive tectonics and a mantle plume beneath the Tarim craton are reported. This Permian history led to the initiation of top-to-the-south thrusting to the south of STS and to the modification of thermal state of the lithosphere beneath the Tarim.The geodynamic model proposed for the Kyrgyz STS fits well with proposed models of global CAOB evolution. Moreover, is shows that the Paleozoic structuration, from the Carboniferous collision to the Permian reactivation, explains the current tectonics of STS which is a doubly vergent mountain belt thrusting intramontane basins to the north and the Tarim craton to the south. This latter acts as a rigid block since the Paleozoic