Tropospheric and stratospheric aerosol particle size, number density, and morphological feature were observed in August, 1993 at Beijing, China (40°N, 116°E). Irregular shape particles, possibly soil particles, were frequently observed in the free troposphere on the basis of scanning electron microscopic measurements of individual particles collected on the surface of carbon-coated nitrocellulose (collodion) films with a balloon-borne particle counter. In the stratosphere the particles with ‘satellite structure’ which has been recognized as a typical feature of sulfuric acid droplets on carbon deposited surface were major particles. Ammonium sulfate particles were frequently identified in the mid troposphere. The number density of the particles with their diameter, d, larger than 0.4 μm was about 3 particles/cm³ near the density peak of the stratospheric aerosol layer, suggesting that the disturbance due to the volcanic eruption of Mt. Pinatubo (1991; Philippine) remained in the stratosphere. Less uniformity in number density profiles of the particles with d ≥ 0.4 μm was observed in the troposphere, suggesting the effect of dynamical air motions with various spacial scales over the Asian continent in summer on aerosol density distributions.