This study presents a comprehensive analysis of Late Neoarchean TTG (tonalite-trondhjemite-granodiorite) within the Longshan Complex, situated at the southwestern margin of the North China Craton (NCC), providing critical constraints on the tectonic evolution of this region. These TTG, located in the Guanshan area of the Long-shan Complex, were dated using zircon U-Pb isotopic analysis, yielding crystallization ages of 2 535~2 485 Ma (2 503±39 Ma, 2 535±39 Ma). The zircon εHf(t) values of the TTG are predominantly positive, and show two-stage Hf model ages ranging mainly from 3.1 Ga to 2.8 Ga. These data suggest that the TTG originated from partial melting of ancient crustal material with contributions from depleted mantle-derived components. Notably, one sample(23LS28) displays uniformly positive εHf(t) values, with some zircons closely approximating the isotopic composition of the coeval depleted mantle. The two-stage model ages for this sample fall within 2.8~2.5 Ga, indicating derivation from partial melting of juvenile crustal material. The TTG exhibit high SiO₂, Na₂O, and low K₂O. Most samples are characterized by flat heavy rare earth element (HREE) patterns, moderately elevated Y and Yb concentrations, low Sr/Y and (La/Yb)_N ratios, and minor to negligible Eu anomalies (δEu = 0.70~0.96). These characteristics suggest that the TTG were generated by partial melting of source rocks under low- to medium-pressure (LP-MP) conditions, with amphibole, plagioclase, and minor garnet as the residual phases. However, one sample (22LS30) exhibits distinct geochemical features, including lower Y and Yb concentrations, higher Sr/Y and (La/Yb)_N ratios, and a pronounced positive Eu anomaly (δEu = 2.47). These attributes indicate a deeper melting environment, corresponding to high-pressure (HP) conditions, with garnet, amphibole, and rutile as the dominant residual phases. The high Mg^#, Cr, and Ni contents observed in all TTG are consistent with geochemical signatures associated with melts derived from the subducted oceanic crust. According to the chronology, isotope geochemistry and petrogeochemistry, these Late Neoarchean TTG belong to the NCC, and may have been in a subduction-related setting at this time. With the increase of subduction depth, the subduction fluid/melt continuously reacts with the mantle wedge, and the mantle interaction continues to strengthen. In addition, this study obtained metamorphic ages of 1 871±26 Ma and 459~335 Ma. The former age is consistent with the metamorphic events dated at 1.97~1.80 Ga in the NCC, while the latter aligns with the Paleozoic metamorphic events in the North Qinling Orogenic Belt. It is concluded that the TTG subsequently experienced metamorphism during Late Paleoproterozoic thermo-tectonic event and were eventually incorporated into the Longshan Complex during the Paleozoic orogenic event.