Always oceanographers pay attention to layer structure in the sea environment. Creation of layer structures is because of some phenomenons like double diffusion, internal waves, turbulence modular mixing. In this paper with examination of vertical structure of temperature, salinity and density between Persian Gulf and Oman Sea in different seasons, layer structures appear clearly. Also, countors of the same physical parameters show the existence of regular structure which prove internal waves resulting from the Persian Gulf and flow into the Oman Sea. The exchange flow through the Stait of Hormus results from horizontal density gradient between the Persian Gulf and Oman Sea. In winter the density ratio ( ) R ρ in this nearshore region is about 0.7 and in offshore region is 0.2. this shows that in this area, double diffusion forms layer structures which have horizontal variations as well as in the vertical. Coastal topography also seems to affect the double diffusion processes and leads to variations of layering in horizontal directions especially between near and offshore regions.