Abstract: Vertical distribution characteristics of aerosols and cloud microphysical properties over the catchment area of the Danjiangkou Reservoir were analyzed based on two aircraft observations conducted on 10 May and 20 May 2024. These missions targeted aerosols and stratocumulus mixed clouds using airborne detection instruments from The results indicate that the aerosol number concentration generally decreases with increasing altitude. Compared with daytime levels, nighttime near-surface aerosol concentrations are higher, reaching up to 4000 cm⁻³. The median volume diameter of aerosols in the middle and lower layers ranges from 0.2 to 0.3 µm, with an effective diameter of 0.6–0.8 µm. Aerosol particles are predominantly concentrated in the small size range, exhibiting a multimodal particle size distribution with the first peak at 0.14 µm. Aerosol concentrations inside clouds are generally slightly lower than those outside clouds, while stronger hygroscopic growth leads to large aerosol particle sizes. Backward trajectory analysis of air masses reveals that near-surface aerosol particles primarily originate from local emissions, whereas high-altitude particles are mainly from long-distance transport. Fine particulate pollution from anthropogenic emissions around the observation site on 10 May was the main reason for the higher near-surface aerosol concentrations observed on 20 May. The effective diameters of cloud droplets within the stratocumulus mixed clouds during both flights were mostly below 25 µm, with maximum cloud droplet number concentrations of 118 and 205 cm⁻³, respectively. The liquid water enrichment layers within the clouds on 10 May and 20 May were located at about 6100 and 5500 m, respectively, with maximum liquid water contents of 0.44 and 0.78 g m⁻³. Due to competition for water vapor by aerosol particles, High aerosol concentrations near the cloud base resulted in elevated cloud droplet concentrations while reducing cloud droplet size. The particle size distribution in the small cloud droplet stage showed a unimodal distribution, with slight variations in peak diameters at different altitudes, predominantly ranging from 11 to 25 µm. The particle spectrum evolved into a multimodal distribution during the raindrop and ice-crystal stages.