In this paper, Laplace transformation method is used to solve the velocity profile and pressure gradient of the unsteady unidirectional flow of Bingham fluid. Between the parallel microgap plates, the flow motion is induced by a prescribed arbitrary inlet volume flow rate which varies with time. Due to the rarefaction, the wall slip condition is existed; therefore, the complexity of solution is also increased. In order to understand the flow behavior of Bingham fluid, there are two basic flow situations are solved. One is a suddenly started flow and the other is constant acceleration flow. Furthermore, linear acceleration and oscillatory flow are also considered. The result indicates when the yield stress τ0 is zero; the solution of the problem reduces to Newtonian fluid.