Abstract: The Haiyuan fault zone and the Zhongwei-Tongxin fault zone are main faults in the northeastern corner of the Tibet Plateau. Basedon analysis of geology and geomor-phology of the region and study on structure and revolution of the two faults, a strain par-tition model is built to adjust the strike slipping and com pressional deformation of the area. Through rupture segmentation study along main faults, rupture units of large earth-quakes are also identified in the region. The seismic tectonic model of the region consists of strain partitioning and fault segmentation.

Key words: Seismic tectonics, Strain partitioning, Fault segmentation, Haiyuan fault