Transport phenomenon within a fluid, namely momentum is plays vital role in nature, industries and all branches of engineering and sciences. The fluids of most interest to engineers are complex in terms of their rheological and transport properties.This study is focused on solution of the boundary layer flow of Casson fluid in a parallel plate channel with different values of Reynolds number. we note that a positive linear relationship between fully developed length and Reynolds number. Horizontal velocity profile of the flow has a parabolic shape when the flow is fully developed.