The Bogda northern margin fault is a regionally active fault in the Bogda Mountain area of the eastern Tianshan and forms the boundary between the northern Bogda Mountains and the Junggar Basin. Investigating its paleoseismic activity is of great significance for understanding the spatiotemporal recurrence of large earthquakes and assessing seismic hazard along the fault. Based on geological and geomorphological field investigations,remote-sensing interpretation,trench excavation,and optically stimulated luminescence(OSL)dating,we examined the paleoseismic characteristics of this fault. the results show that the trench profiles record two reliable paleoseismic events,which occurred at approximately (20.79±1.24)～(14.55±0.76)ka and (14.55±0.76)～(8.94±0.45)ka,respectively. Evidence from the trench profiles further indicates that no significant surface-rupturing earthquake has occurred along the fault during at least the past 8.94ka,suggesting that the elapsed time since the latest event exceeds 8.94ka. Based on empirical relationships involving fault slip rate and elapsed time,the current accumulated vertical displacement along the fault is estimated to be approximately 2.59m. Estimates derived from two empirical formulas indicate that the Bogda northern margin fault has the potential to generate a strong earthquake of magnitude 7.0～7.5. Therefore,the fault is considered to pose a high seismic hazard in the future.