We experimentally observed properties of liquid film breakup for shock-wave-initiated disturbances in air at normal temperature and pressure. The tested liquids include water and various glycerol mixtures. High speed camera and multiple-spark high speed camera were utilized to record the process of liquid film breakup. A phase Doppler particle analyzer was also used to record droplet size and velocity. The experimental results show that liquid viscosity plays a vital role in the deformation, breakup and atomization of liquid films. After the interaction of shock waves, the droplet size of various glycerol mixtures is significantly smaller than either water or glycerol. Richtmyer–Meshkov instability is an important factor in the breakup and atomization of liquid films induced by shock waves. Furthermore, a dispersal model is established to study breakup mechanisms of liquid films. The correlation between droplet size and velocity is revealed quantitatively. The research results may provide improved understanding of breakup mechanisms of liquid films, and have important implications for many fields, especially for heterogeneous detonations of gas/liquid mixtures.