The effect of pulsating magnetic fields on the transient outward K⁺ channel of rat cortical neurons was researched.This experiment used pulsating magnetic fields with frequency of 15 Hz and intensity of 1.4 mT to impose on acutely the isolated rat cortical neurons,and studied the properties of transient outward K⁺ channel using the whole-cell patch clamp technique.The experiment reveals that pulsating magnetic fields reduce the amplitude of I_A,and significantly affect the activation process of I_A.The half-activation voltage and the slope factor of the activation curve are changed by the pulsating magnetic fields' exposure from(13.25±2.22) mV to(30.98±4.11) mV(n=6,P<0.05)and from(24.00±2.05) mV to(23.30±2.13) mV(n=6,P>0.05),respectively.The results show that pulsating magnetic fields can change the properties of transient outward K⁺ channel and can adjust the physiological functions of neurons by the pulsating magnetic fields.