Abstract: Ore genesis of Taibai-Weishan big polymetallic deposit was presented, and the ore deposit forming time from 140 Ma to 132.2Ma. There are two series of late Jurassic volcanics at the area, and the late stage rhyolitic lavas are metallogenic parent rocks. Lithofacies and geological characters of the late stage rhyolitic lavas were described. The REE elements characters show homology of orebodies, volcanics and subvocanic rocks, and they came from refusion of upper crust, and suffered strong fractionation. Primary structure features and forming time of the ore district were revealed, and multi-scale nappe structure overprinted on the NE-trending fracture structure system with rapid regional uplifting. The north-east fracture structure and multi-scale nappe structure of the ore district are the third level controling structures of rock and ore. Explosive breccias are also the favorable pathway and reservoir space of ore fluid. The area are prospective for more ore deposits.