Abstract: Snow avalanche is one of the most common geological disasters ubiquitously distributed in the Qinghai-Tibet Plateau. Snow avalanche susceptibility mapping is critical for disaster prevention and mitigation of major engineering construction such as the Sichuan-Tibet Railway. This paper exemplifies the Parlung-Tsangpo catchment in south-eastern Tibet, collects 381 channelled snow avalanches that fell below the timberline through field surveys and remote sensing interpretation. First of all, 18 influence factors are selected and quantitatively extracted by using GIS, remote sensing, et al. Then, Principal Component Analysis(PCA)method is performed to obtain the key predisposing factors and assign weight coefficient to each factor. Thereafter, the Weighted Information Value Method(PCA-Ⅰ) and Weighted Certainty Factor Method(PCA-CF) are conducted to map snow avalanche susceptibility. Finally, the performance of two models is compared and evaluated based on ROC(receiver operating characteristic) curve and AUC(area under receiver). The results show that the susceptibility assessment is very sensitive to climate, macro-topography, micro-topography, and inhibition factors. Among them, the climate explained 30.61% of the data variation; topography explained 21.23% of the data variation. The PCA-Ⅰ model gives the susceptibility zoning index in the range of -2.41, 1.365, and the PCA-CF model gives the susceptibility zoning index ranging in-0.549, 0.424. In addition, the susceptibility map of the PCA-Ⅰ model has a significant abnormal area in downstream at the Tongmai section. Thus, the zoning index of the PCA-CF model is more reasonable than that of the PCA-Ⅰ model. The overall results suggest that the high snow avalanche prone areas are mainly distributed at Ranwu-Yupu section along the National Road 318 around in the upper narrow valley section of Parlung-Tsangpo river, the ridges of the mountains on both sides of the middle and lower reaches, and the narrow valley sections of the tributaries.