Abstract：Understanding the composition and formation conditions of regional airborne pollen is helpful to clarify the environmental significance of different pollen assemblages. The Burkard pollen trap was used to observe airborne pollen on the northern slope of Mount Qomolangma for two consecutive years (2012 and 2013). Based on backward air mass trajectory model and source receptor models, the pathway and potential source of Alnus pollen which is the main component in autumn were discussed. The relationship between Alnus pollen and plant distribution and atmospheric circulation were analyzed as well as its environmental significance. Three main results were obtained. First, the air mass transport pathway during Alnus pollen season mainly came from the southwest direction of the sampling site. Second, the potential source area of Alnus pollen was mainly located in the middle Himalaya region including central and eastern Nepal, southern Tibet, etc, which is basically corresponded with the main air mass transport pathway. Third, the interannual changes of Alnus pollen quantity, transport pathway and potential source area may be related to atmospheric circulation. The southwest air mass influenced by upper westerly had a stronger influence on Alnus pollen. The results provide foundational insights into the climatic significance of exotic pollen on the northern slope of the Mt. Qomolangma region.