In this paper, we investigate the shock wave dissipation in a gas-droplet mixture over a wedge. A similar gas-droplet mixture had been considered earlier but this time we take account of breakup of the large droplets and see how the shock wave is affected. We consider a droplet breakup model dependent on the critical Weber number and add the equation of droplet number density evolution to the compressible two-fluid model. The viscous drag force, the heat transfer, and the phase change of the droplets are all included in the present model for interaction between phases. The fractional step method is used to solve the two-fluid governing equations in two parts: the hyperbolic operator is solved by the second-order WAF-HLL scheme and the source operator by the fourth-order Runge-Kutta method. We elaborate how the shock dissipation and pressure distribution is affected by the droplet size and droplet volume fraction. (C) 2011 Elsevier Ltd. All rights reserved.