The Xiangshan volcanic-intrusive complex consists of Late Mesozoic acid pyroclastic rocks interbedded with sedimentary rocks, acidic lava, intermediate-acidic shallow-ultrashallow intrusive rocks, composed mainly of clastoporphritic lava, granitic porphyry and rhyodacite. The magmatic activity started with the eruption, experienced mainly volcanic effusion and ended at shallow_ultrashallow magmatic intrusion. The rhyodacite, once as the overfall facies, belongs to 2ndmember of Upper Jurassic Daguding Formation. The single-zircon U_Pb dating of the rhyodacite shows that the age of the rhydacite is 129.54±7.93 Ma, younger than the age of clastoporphritic lava which is the principal part of Xiangshan volcanic-intrusive complex. Combined with the modes of occurrence and shape characteristics of the rhyodacite, this paper holds that rhyodacite is apost-volcanic shallow or ultrashallow intrusive body, i.e., rhyodacitic porphyry. According to the age data available and the borderline age of 145.5 Ma between Jurassic and Cretaceous, the authors consider that the formation age of the complex is Early Cretaceous.