Abstract: The middle-sized Guandi electrum deposit occurs in the early Yanshanian diorite and subvolcanic rocks. The ores are closely related to the subvolcanic rocks in both space and origin. The subvolcanic rocks are not only the wall rocks but also the parent rocks for the ores. Moreover, the Permian andesite is another ore-forming country rock. The metallogenesis is achieved under the conditions of low temperature, low pressure and atmospheric precipitation. The main controlling factors for the mineralization include favorable source beds and volcanic edifices.