The Yandang Mountain World Geopark situated in southeastern Zhejiang province is mainly a Cretaceous resurgent caldera composed of four volcanic rock sections and one central intrusive body. It has undergone four stages of eruptio, two collapses, one intrusion and the formation of modern landscape, comprising totally eight evolution phases. Volcanic rocks are of the high-K calc-alkaline series rock association, composed mainly of ryholitic and trachytic dacitic rocks, and the central intrusive body is olivine-andesite-trachytic quartz syenitic porphyrite. They have A/CNK values of 0.9～1.2, suggesting aluminum saturation or ersaturation, and are enriched in LREE and LILEs and depleted in HFSEs. Their δEu values are 0.11～0.32, evidently indicating plagioclase fractional crystallization. (87Sr/86Sr)i ratios and εNd（t）values are 0.707?9～0.716?1 and -6.90～-7.70 for volcanic rocks, and 0.7086～0.7098 and -7.10～-7.68 for quartz syenitic porphyrite, respectively, implying that all the igneous rocks from the Yandang Mountain were evolutional products of co-magmas, and derived mainly from the crust, mixed however with mantle components. The tectonic setting is an active continental margin close to the inner continent instead of a typical island arc or an Andean_type active continental margin.