High-resolution satellite image interpretation and field investigation indicate that the surface rupture zone produced by the Yutian MS7.3 earthquake is ~25 km long along a NS-trending fault at the western piedmont of a snow-covered range at the upper reach of the Yurungongkash River, about 20 km south of the Ashikule Volcanoes. The surface rupture zone consists of different striking ruptures with both normal and left-lateral faulting components. The maximum left-lateral and vertical co-seismic slips measured in the field are ~1.8 m and ~2.0 m, respectively. Its seismogenic NS-trending fault belongs to the secondary structure at the NE-trending tensile area of the southwestern end of the Altyn Tagh Fault, which conforms to the eastward escape of the Kunlun-Qaidamu-Qilian block, relative to the