A suite of Late Paleozoic Hadamiao quartz diorites were discovered in the northern part of the North China Platform within eastern Central Asia Orogen, which were previously considered to be products of Yanshanian intrusion and fractionation. U-Pb age dating with the LA-ICP-MS method yielded 272.9±2.4 Ma (MSWD=2.0), which represents the crystallization age of the quartz diorites. The Hadamiao quartz diorites and the associated Hadamiao auriferous granitic porphyries all show features of high-potassium and calc_alkaline I-type. The quartz diorites can be distinguished from the auriferous granitic porphyries in high content of Al2O3, FeOT, CaO, MgO, TiO2, Sr, high mantle components（Co, Ni, Cr, Mn）, and low content of SiO2, K, Ta, Th, U. The total REE content is quite low, lower than the REE content of intermediate rocks in the crust (∑REE=196×10-6) and that of acid rocks in the crust（∑REE=290×10-6）. LREE is evidently enriched, and medium to weak negative anomalies of Eu can be seen. The granitic porphyries are stronger than the quartz diorites in the fractionation between LREE and HREE and the manifestation of negative anomalies of Eu. Compared with the primitive mantle, they are obviously enriched in LILE (K, Rb, Th, Zr, Hf ) and depleted in HFSE (Nb,Ta, Ti, P) , indicating features of SZC and continental arc. Both the quartz diorites and the auriferous granitic porphyries show features of fore-collision and syn-collision between plates. An isotopic analysis of Sr, Nd and Pb reveals that the original rocks of the Hadamiao complex were derived from the mixture of the crust and the mantle, assuming characteristics of newly-formed lower crust (paleoisland arc). The model ages of Nd (tDM=1054～1260 Ma) in Hadamiao area are comparable with those of the Bainaimiao arc greenschists (1130±16 Ma), suggesting the existence of some genetic relations. The relation graph of La/Sm versus La and the changing degree of the magma concentrations indicate that the quartz diorites were formed by crystallization separation whereas the auriferous granitic porphyries were produced through partial melting. The early separation of the biotite quartz diorites provided preferential conditions for Au concentration in the bodies of granitic porphyry within the sulfide-poor porphyry gold deposit. The abnormal enrichment of hydrophile elements (Rb, Ba, Th, U, K) in the Hadamiao auriferous granitic porphyries can be used to distinguish auriferous granites from barren granites. Therefore, this paper supplies prospecting clues to the gold deposits related to the Paleo-Asia Ocean subduction and accretion leading to collision in the Late Paleozoic.