Abstract: According to the characteristics of SDZ-30B0 dual induction-eight lateral logging instruments,SP logging principle and SP application,analysis has been conducted about induction logging SP anomaly,mainly from the aspects of the focus circuit and isolation circuit of the dual induction instrument,the SP ring,and the SP signal channel.In addition,the thought and solution methods have been put forward.These solution methods can improve the success rate of spontaneous potential curve,divide reservoirs,judge lithology and oil and gas layer,and improve the quality of logging.