The NS or NE SW trending Gaoligong metamorphic belt lying in western Yunnan Province is distributed along west Gaoligong strike slip shear zone. Its thermal evolutional history and deformed ages has been an issue of little consensue. This study conducted 40Ar/39Ar dating by using Laser 40Ar/39 VG5400 and conventional 40Ar/39Ar dating system for granitic mylonite, granitic gneiss, amphibolite xenolith and mica schist from the Gaoligong metamorphic and deformational zone. The 40Ar/39Ar dating results range from 33.7~10.18Ma, and K Ar ages concentrate about 10~13Ma and 16.7~22.8Ma. Based on field geologic features and the characteristics of the microstructure, the metamorphic rocks deformation of Gaoligong metamorphic belts began after ~35Ma. Combined with 40Ar/39Ar chronologic result and fission track data in the study area, the thermal evolution history of the metamorphic belt shows that the paleogeothermal temperature of the Gaoligong belt was down to 300~350℃ at 24Ma accompanied by partial mafic magma emplacement and uplifting, and continued to cool down 220~300℃ at 10~12Ma, and had a slow cooling process before down to 60~120℃ at 5.5Ma. The thermochronology ages may indicate the uplift amplitude difference from south to north.