Profiles of salinity and temperature were measured in the strait of Hormuz(SH) during the winter of 2012, spring and summer of 2013. To investigate the double diffusion(DD) processes, Turner(TU) angle values are calculated in all the stations in the SH. Different TU angle values correspond to salt fingering(SF), diffusive convection(DC)and stable stratification. The distributions of the two forms of DD were plotted vertically along transects in the eastern, central and western part of the SH, and corresponding DD processes were described. The results show that both SF and DC occurred in most part of the study area. Two different water masses(the Indian Ocean surface water and the Persian Gulf water) were evident at the SH, and SF and DC were evident at the interface of two water masses. Due to evaporation, SF occurred in the surface layer of most Stations throughout the year. In the eastern part of the SH, occurrences of DC were more feasible in wintertime. SF was the main phenomenon at the end of hot season. For central part, SF occurred throughout the year in water column. In the western part,water column was stable in summer and DC happened in most part of water column in winter. Profiles of salinity and temperature were measured in the strait of Hormuz (SH) during the winter of 2012, spring and summer of 2013. To investigate the double diffusion (DD) processes, Turner (TU) angle values ​​are calculated in all the stations in the SH. Different TU angle values ​​correspond to salt fingering (SF), diffusive convection (DC) and stable stratification. The distributions of the two forms of DD were plotted vertically along transects in the eastern, central and western part of the SH, and corresponding DD processes were described. The results show that both both SF and DC occurred in most part of the study area. Two different water masses (the Indian Ocean surface water and the Persian Gulf water) were evident at the SH, and SF and DC were Due to evaporation, SF occurred in the surface part of the year, the incidence of of the DC were more feasible in wintertime. SF was the main phenomenon a t the end of hot season. For central part, SF occurred throughout the year in water column. In the western part, water column was stable in summer and DC happened in most part of water column in winter.