Aim To determine the effects of aerobic exercise training on aging-associated selective changes of the function of the spontaneous transient outward currents and the large-conductance Ca²⁺-activated K⁺ channels in cerebral arteries. Methods Male Wistar rats aged 19～21 months were randomly assigned to sedentary （O-SED） and exercise-trained groups （O-EX）.Two-month-old rats were used as Young control.After 12 weeks,the segment of cerebral arteries was carefully dissected free,and separated into smooth muscle cells by two steps digestion. Results Whole-cell patch clamp showed that aging decreased the density of whole-cell K⁺ current and iberiotoxin-sensitive whole-cell K⁺ current； The amplitude of spontaneous transient outward currents was decreased by aging， while there was no significant difference in the frequency； Inside-out patch clamp recording on cerebral arteries myocytes showed that aging decreased the open probability and Ca²⁺/voltage sensitivity of single large-conductance Ca²⁺-activated K⁺ channel； The opening time was decreased by aging,whereas the close time was increased.However,exercise training inhibited all of these changes. Conclusion These data suggest that regular aerobic exercise can attenuate the functional downregulation of spontaneous transient outward currents/large-conductance Ca²⁺-activated K⁺ channels in aging cerebral arteries myocytes,which may be one of the important mechanisms underlying the beneficial effects of aerobic exercise on aging arteries.