Low-pressure impaction of fine ice particles has been experimentally investigated. First, aerosols consisting of fine water droplets were prepared by two-fluid and ultrasonic nebulizations, and water-vapor condensation. The average size and total number concentration of the droplets were controlled in wide range by the preparation methods and the process variables set for each preparation. The aerosols were next cooled by heat transfer in liquid nitrogen bath and the droplets were solidified. Finally, high-velocity jet of the ice particles was produced by expansion through a nozzle into low-pressure chamber where a substrate is impacted by them. The strength of impaction on the substrate varies with the chamber pressure, impaction angle, and nozzle-to-substrate distance as well as the size and number concentration of the ice particles.