Abstract: The black-necked crane (Grus nigricollis) is a first-class nationally protected species in China with its distribution influenced by various habitat factors． Studying the relationship between distribution of black-necked cranes and habitat factors in areas affected by power transmission and transformation lines is of great significance for their conservation． In this work, a 100-kilometer buffer zone on both sides of a transmission line was studied． principal component analysis (PCA) combined with variance inflation factor (VIF) method was used to screen key habitat factors. A generalized additional model (GAM) was then constructed to predict relationship between black-necked crane distribution and these factors． The distribution density of black-necked cranes was found significantly correlated with five habitat factors: elevation, NDVI, distance to water sources, distance to roads, and mean temperature of the wettest quarter． NDVI and distance to roads showed significant positive correlations with crane density, while distance to water showed a significant negative correlation． The highest distribution density occurred at elevations between 3 500 and 4 500 meters, wettest quarter temperatures ranged from 6 to 12 °C． It is concluded that quantitative relationship between black-necked cranes distribution and key habitat factors could be established and this will provide scientific support for ecological protection in power transmission project areas．