The present work investigates the propagation of incident and reflected shock and rarefaction waves in a homogeneous mixture of gas and liquid droplets in shock-tubes. Two models describing the break-up process of drops exposed to blasts of air were used. The governing enuations were solved using the Particle-In-Cell (pic) method, and was developed specif-ically to be run on a micro-computer, and to overcome the disadvantages of relatively low speed and limited memory resources of micro-computers compared to main frames. The numerical solution remains stable for low and moderate droplet volume fractions and the predicted velocity,pressure and temperature flow fields for the gas and droplet phases aptly illustrate the capability of the method to treat the complex coupling phenomena associated with multi-phase flows and shows its dependence on the physical properties of both gas and droplets.