An MS7. 3 earthquake happened on February 12，2014 in Yutian county，Xinjiang Uygur Autonomous Ｒegion，which was followed by a series of aftershocks． It is very important work to determine the depth of seismic sequence timely． Accurate determination of the focal depths of the foreshock，main shock and aftershock sequence can provide more information about fault structure，source process，crust and mantle structure，the motion of the plates and a series of problems． The paper uses a deterministic method for determination of earthquake depth to measure the depths of Yutian MS7. 3 seismic sequence in Xinjiang． The original phases data are adopted from the catalog database of China Earthquake Networks Center，combined with seismic wave records from the Digital Seismic Network Center，Earthquake Administration of Xinjiang Uygur Autonomous Region．