In order to study mineral composition and morphology of atmospheric dust fall and to estimate the source of the particles, the authors employed XRD and SEM/EDX to perform investigations in such aspects in Changsha City. The results reveal that the main minerals are illite, plagioclase, chlorite, quartz, calcite, dolomite and amorphous matter, with the illite and chlorite derived from the surface raised dust, and the amorphous from the industrial ash. There are four morphological types, namely grained and flaky individual mineral, chain-like aggregates, spherical flying beads and irregular aggregates, with the chain-like and spherical aggregates being indicators of industrial ash, and other particles derived from other sorts of raised dust. The mineral composition and morphology of atmospheric dust fall serve as important criteria in identifying pollution sources.