Mean velocity and turbulence together with pressure distributions in a radial free jet flows were studied. By changing diameter and width of nozzles and discharge velocity, the flow pattern were measured. The concept of the equivalent nozzle width which contains the diameter and width of the nozzle can be usefully applied to describe both maximum flow velocity decay and growth of the jet half width with distance from a nozzle outlet. The maximum flow velocity decay and the growth of the jet half width lie on a single curve according to this equivalent nozzle width. In the main region at large nozzle Reynolds number, the maximum flow velocity decays following the same rule as in circular jet, and the growth of the jet half width is in good agreement with that in the two-dimensional jet.