The East Kunlun active fault zone, which lies in the valley of the Kunlun Mountains above an elevation of 4,000 meters, is an important active fault zone in the Northeast Qinghai-Xizang (Tibet) Plateau. The 1937, the Tosonhu lake M_S7.5 earthquake occurred in the eastern segment of the East Kunlun active fault zone. Four field investigations were launched on this seism in 1963, 1971, 1980, and between 1986 and 1990. However, due to different extents of the investigations, four different conclusions have been gained. Concerning the length aspect of the surface rupture zone of this earthquake, the unanimous consensus is that its eastern end lies in the west side of the main Ridge of the A’nyêmaqên Mountains, but opinions about the western end and the location of the macro-epicenter are different. Based on investigation and comprehensive study, a series of scientific problems like geometric and kinetic characteristics, the length of the rupture zone, the maximum sinistral horizontal displacement and the macro-epicenter were re-evaluated. We believe that the total length of this earthquake’s surface deformation zone is at least 240km; the western end of the zone is at the west of Wusuwuwoguole; the maximum sinistral horizontal displacement is 8m to the west of Baerhalasha gully on the east side of Sanchakou; the maximum vertical displacement is 3.5m in the south of Sanchakou and the macro-epicenter is in Sanchakou. The East Kunlun active fault zone, which lies in the valley of the Kunlun Mountains above an elevation of 4,000 meters, is an important active fault zone in the Northeast Qinghai-Xizang (Tibet) Plateau. The 1937, the Tosonhu lake M_S7.5 earthquake occurred in the eastern segment of the East Kunlun active fault zone. Four field investigations were launched on this seism in 1963, 1971, 1980, and between 1986 and 1990. However, due to different extents of the investigations, four different arena were managed Concerning the length aspect of the surface rupture zone of this earthquake, the unanimous consensus is that its eastern end lies in the west side of the main Ridge of the A’nyêqên Mountains, but opinions about the western end and the location of the macro Based on investigation and comprehensive study, a series of scientific problems like geometric and kinetic characteristics, the length of the rupture zone, the maximum sinistral horizontal dis placement and the macro-epicenter were re-evaluated. We believe that the total length of this earthquake’s surface deformation zone is at least 240km; the western end of the zone is at the west of Wusuwuwoguole; the maximum sinistral horizontal displacement is 8m to the west of Baerhalasha gully on the east side of Sanchakou; the maximum vertical displacement is 3.5m in the south of Sanchakou and the macro-epicenter is in Sanchakou.