Jet flow phenomenon is one of the basic flows in the fluid mechanics because it includes the free and wall bounded turbulent shear flows and large-scale vortex structure, and so on. It is used widely in the field of industry for the operations of heating, cooling, mixing and diffusion. In order to improve the mixing and diffusion characteristics between the jet and surrounding various non-circular nozzles have been tried. In this research, the flow characteristic, mixing and diffusion properties, of free jet from the petal-shaped special nozzle with six petal-shaped protrusions are made clear experimentally. It is expected that petal-shaped free jet will have a good mixing and diffusion characteristics because of a large wet length, perimeter, and large vortex structure.