首先介绍了2014 年2 月12 日新疆于田MS7. 3 地震的区域构造背景与断裂活动情况;然后分析了此次MS7. 3 地震震中位置以及周边历史地震震源机制特征，认为2014 年2 月12 日于田MS7. 3 地震发生在阿什库勒断裂东支上，2014 年MS7. 3 地震和2008 年MS7. 3 地震是阿尔金断裂带南端尾部向西南方向延伸，由左旋走滑为主逐渐转变为拉张作用为主的过程中，在阿什库勒断裂带不同位置发生的2 次地震，它们存在着相同的力源作用，2008 年MS7. 3 地震对2014 年MS7. 3 地震的发生有促进作用;最后利用分层地壳模型计算了2008 年MS7. 3 地震对2014 年MS7. 3地震的库仑应力作用，结果同样显示2008 年MS7. 3 地震促进了2014 年MS7. 3 地震的发生。

The regional tectonic background and characteristics of active faults of the Yutian MS 7. 3 earthquake on February 12，2014 are discussed in the paper． After the analysis of the epicenter of the MS 7. 3 earthquake in 2014 and focal mechanism of former strong earthquakes around it，the authors deduced that the seismogenic fault of the MS 7. 3 earthquake is the east branch of the Ashikule fault． The MS7. 3 earthquake in 2014 and the MS7. 3 earthquake in 2008 are two strong earthquake events on the different section of the Ashikule fault，where the fault behavior changes from the sinistral slip to normal because of the extensional tail effects in the southern end of the Altyn tagh fault． It is concluded that the two MS7. 3 earthquakes have the same dynamic source，and the MS7. 3 earthquake in 2008 promotes the occurrence of the MS 7. 3 earthquake in 2014． Finally，the authors calculate the coulomb stress change to seismogenic fault of the MS7. 3 in 2014 from the MS7. 3 earthquake in 2008 using the layered crust model． The result also shows that the MS 7. 3 earthquake in 2008 accelerated the occurrence of the MS 7. 3 earthquake in 2014．

“十二·五”国家科技支撑计划项目(2012BAK19B02)资助