Drag reduction of laminar flow in microchannel is very important for μ-TAS (Micro Total Analysis Systems). Ceramic substrates which consist of alumina particles have rough surface and it is used as a mold to fabricate PDMS rectangular channel with textured wall. Roughness of the wall is depended on diameter of alumina particles. Velocity profile of laminar flow in a textured channel is measured by micro PIV. The measurements reveal that reduction in textured channel can be achieved relative to the classical smooth channel Stokes flow.