Field emission scanning electron microscopy (FESEM) was used to study the aerosol samples collected in Nam Co and air of Shangri-La under different weather conditions during July～August, 2011. The results showed that particles could be subdivided into 5 major morphological categories, namely soot aggregates, spherical particles (tar ball and fly ash), spherical particles, mineral particles and bio-particles. There existed fly ash in Shangri-La aerosol samples, which however did not exist in Nam Co. Number-size and volume-size distribution of particles in Nam Co aerosol samples displayed peaks in the size range of 0.2～0.3 μm and 1～2.5 μm. The proportion of quantity(44.4%)and that of volume(61.7%)of mineral particles were the highest; size distribution of particles in Shangri-La aerosol samples displayed two major peaks in the size range of over 2.5 μm. The proportion of quantity (51.7%) and that of volume (58.7%) of mineral particles were the highest. Fine particles and coarse particles were the major types of aerosol samples of Nam Co and Shangri-La respectively. The amount (44.4%) of mineral particles was the highest in Nam Co, followed by soot aggregates (29.5%) and spherical particles (26.1%). The quantity proportion (32.59%) of Nam Co aerosol samples was mainly in the size range of 0.2～0.3 μm. Mineral particles were the highest (15%), followed by spherical particles (11.5%) and soot aggregates (6.1%). The quantity proportion (37.5%) of Shangri-La aerosol samples was mainly in the size range of over 2.5 μm. Mineral particles were the highest (17.9%), followed by spherical particles (10%) and soot aggregates (9.6%).