Oxygen fugacity reflects information, such as temperature, pressure and composition of the magma, and now, the calculation of zircon Ce( IV)/Ce(III) ratio is an effective method to indicate the feature of magma oxygen fugacity. This paper analyze the zircon Ce( IV)/Ce (III) ratio of intrusions in Beiya gold-polymetallic deposit. Beiya super-large gold deposit is located in the central part of the Jinshajiang-Ailaoshan potassic magmatic rocks belt and develops a gold-polymetallic metallogenic system which is closely related with potassic intrusive rocks. The intrusive rocks which lie different positions of the stock which formed before the mineralization are all analyzed, and the result shows that the average Ce(IV)/Ce(III) ratio of intrusive rocks which locate in the edge of the stock is higher than those in the inner zone of the stock, that is indicates that oxidation states of intrusive rocks which lie outer zone of the stock is stronger, and individual zircons have a large range of Ce (IV)/Ce (III) ratios, this situation maybe affect by the spatial site distribution of intrusive rocks. Analysis of zircon Ce (IV)/Ce (III) ratios of Beiya and other typical deposits in potassic magmatic rocks belt reveal that the ratios are various in different deposits. The intrusive rocks with high Ce( IV)/Ce(III) ratios do not necessarily indicate they are metallogenic rocks, it needs to refer to the average of a serial of single-point Ce (IV)/Ce (III) values analyzed in a plane.