Flow structures behind two different sized flat plates in tandem arrangement normal to flow at high Reynolds number have been investigated experimentally. A narrow flat plate, as a control plate, has been placed upstream of a wide plate to investigate the interacting wakes behind the wide flat plate. The near wake downstream of the wide plate has been measured by employing constant-temperature hot wire anemometer, quantitatively. The effects of different width ratio (h/D) range from 0.1 to 1.0 together with gap ratio (g/D) ranging from 0.5 to 2.0 have been probed. It was found that Strouhal number variation is directly proportional to gap ratio between the plates. Moreover, it was observed that turbulent kinetic energy production is mostly contributed by transverse normal turbulent stress and therefore follows the transverse stress pattern rather than the stream wise stress.