Hydrodynamic interaction between two identical rising solid spheres stainless steel, glass and plastic at different sizes and densities arranged in two configurations; side by side and in line, under the action of external driving force and along the axis of a cylindrical column, was investigated theoretically and experimentally in non Newtonian fluid type power law fluid Flow visualization; the motion of two identical spheres stainless steel both accelerating from rest under the action of gravity at the same time along the center line of a cylindrical. The two spheres are arranged side by side and in line.