Based on the collection and analysis of achievements of other scholars, and by consulting the results of seismic safety evaluation of engineering sites and field surveys of recent years, the seismotectonic indicators are determined for northwest Yunnan and its vicinity, and then potential seismic sources are further delineated. In practice, the following principles are applied: for areas with strong historical earthquakes, the recurrence principle is used to determine the upper bound magnitude; for areas with distinct seismogenic structure but no historical strong earthquake records, the tectonic analogy principle is used in the light of the size and activity behavior of the structure; for areas where the segmentation of the active fault is well studied, the potential sources will be demarcated more precisely; and for areas with buried fault, the seismicity pattern and geophysical abnormity are used to determine the direction of the major axis of the potential seismic source. Based on the collection and analysis of achievements of other scholars, and by consulting the results of seismic safety evaluation of engineering sites and field surveys of recent years, the seismotectonic indicators are determined for northwest Yunnan and its vicinity, and then potential seismic sources are further In practice, the following principles are applied: for areas with strong historical earthquakes, the recurrence principle is used to determine the upper bound magnitude; for areas with distinct seismogenic structure but no historical strong earthquake records, the tectonic analogy principle is used in the light of the size and activity behavior of the structure; for areas where the segmentation of the active fault is well studied, the potential sources will be demarcated more precisely; and for areas with buried fault, the seismicity pattern and geophysical abnormity are used to determine the direction of the major axis of the potential seismic source.