Abstract: Located in the south margin of Shangdan sunduction–accretion belt, intrusive rocks in Shanyang–Zhashui region are mainly formed in two stages: the former is Neoproterozoic (885～621 Ma), and the latter is Middle–Late Triassic and Early Cretaceous (233～132 Ma) that was a result of Qinling orogenic event during Indosinian–Yanshan period. Zirons LA–ICP–MS U–Pb dating of intrusions in Tudigou–Chigou region show them formed between 144.4 Ma and 158.8 Ma, during Late Jurassic and Early Cretaceous. Geochemical study on these rocks reveals, they are enriched in large ion lithophile element (LILE) and depleted in high field strength elements (HFSE), with a high ratio of Sr/Y. Combined with the research on regional magmatic evolution, intrusions formed between Late Jurassic and Early Cretaceous in Tudigou and Chigou may be controlled by the movement of western Pacific and NE faults. And also, with the crustal delamination and the addition of fluid from subduction–accretion belt in post–collision and post–orogenic stages, intrusions from Shanyang– Zhashui region are formed by the melting of crust in Middle–south Qinling.