The Longshan Complex, distributed in Baoji of Shaanxi Province and Tianshui of Gansu Province, is located at the junction of the Qinling orogenic belt and the Qilian orogenic belt, and is the material basis for understanding the tectonic evolution and attribution of the region. In this paper, detailed petrography, mineral chemistry, phase equilibrium modeling and titanite U-Pb geochronology studies were carried out on garnet-bearing amphibolites samples collected from the Longshan Complex.Based on detailed petrographic observations and mineral chemical analyses, it was determined that the garnet-bearing amphibolites recorded three stages of metamorphic mineral assemblages. The mineral assemblage in the prograde metamorphic stage (M1) is represented by fine-grained plagioclase, amphibole and quartz in garnet; the mineral assemblage in the peak metamorphic stage (M2) is represented by plagioclase+amphibole+quartz+garnet+ilmenite+titanite+melt; and the mineral assemblage in the retrograde metamorphic stage (M3) is represented by plagioclase+amphibole+quartz+ilmenite+melt, forming a symplectite texture.According to the geothermobarometers, the temperature and pressure conditions in the prograde metamorphic stage (M1) are 563℃ and 0.82 GPa. The results of phase equilibrium modeling for the peak metamorphic stage (M2) show that the temperature and pressure conditions are 800~818℃, 1.28~1.32 GPa and 740~770℃, 1.17~1.20 GPa. For the retrograde metamorphic stage (M3), the temperature and pressure conditions of one sample calculated by phase equilibrium modeling are 691~703℃, 1.03~1.06 GPa, and the temperature and pressure conditions of another sample obtained by the geothermobarometer are 683℃ and 0.8 GPa. The amphibolites have experienced the prograde metamorphic stage to the peak metamorphic stage and then to the retrograde metamorphic stage, and recorded a clockwise metamorphic p-T path. The peak metamorphic temperature and pressure conditions are close to or similar to those in many areas of the Qinling Complex. The results of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) titanite U-Pb geochronology show that the intersection ages of titanite in the garnet-bearing amphibolites are 380.5±4.8 Ma, 430.8±6.7 Ma, 431.6±6.1 Ma and 433.4±4.0 Ma. In summary, by comparing the metamorphic temperature and pressure conditions and metamorphic ages of the Longshan Complex with those of the Qinling Complex, it was found that the metamorphic age of the Longshan Complex in this region is close to the last retrograde metamorphic age of the Qinling Complex in the eastern section of the North Qinling, and the peak metamorphic temperature and pressure conditions are similar to the granulite facies metamorphism of the Qinling Complex in the western section of the North Qinling. It is speculated that the Longshan Complex may be the western extension of the North Qinling orogenic belt.