Abstract: The effects of substrate elasticity on instability anddynamics of the horizontal evaporating ultra-thin liquid film areinvestigated in the present study. The evolution equation for the thicknessof liquid film is derived based on long-wave approximation. The effects ofsubstrate elasticity, Van der Waals forces and evaporation of liquid areexamined by both linear stability analysis and numerical simulation. Theresults indicate that increasing substrate elasticity or decreasing thesurface tension of liquid can enhance the development of perturbations,change the wavelength of interfacial wave, and be helpful to the rupture ofthe liquid film. The evaporation of liquid will promote the instability offilm and accelerate the rupture process.