Abstract: The Pliocene shield volcanic mechanism in Nashan, Yizheng of Yangzhou displays an eruptive recycle of explosive-effusive-subvolcanic facies, accompanied with multiple parasitic craters. It is the only one with complete volcanic relic in Jiangsu province and rare in China. This paper systematically describes the Pliocene shield volcanic mechanism in Nashan and analyses the origin and geological features in details. This is the first research conducted in the area and therefore has great significance to the protection and development of the geological relic because it is the most important geological resources for geological scientific research, science education, and ecological tourism.