A three dimensional numerical model namely, (Princeton Ocean Model) and some observational data are used to study the Persian Gulf outflow structure and its spreading pathways during two different time of the year, mid-winter and early summer. A few available observations show that the Persian Gulf outflow source water exhibits seasonal variations in temperature and salinity. The numerical model is set up by CTD measurements at its western boundary and monthly surface wind speed on the model domain from ICAODS data. The results show that the outflow originates from two branches at different depths in the Persian Gulf. The permanent branch that may exist during the whole year in deeper parts at about 40 m and originates from inner parts of the Persian Gulf and the other one is a seasonal branch that starts to form the vicinity of southern coast during winter months (February). Near the Strait of Hormuz the two branches are jointed together and form the main outflow source. Our findings reveal that during the winter the outflow boundary current detaches from the coast just at the Ras Al Hamra Cape, however for the summer the outflow seems to follow the coast even after this Cape, and appears to separate from the coast at the Ras Al Hadd Cape. This behavior is explained as follow: more saline outflow during February causes higher density and so sinking to deeper zone during the winter. Thus, it moves to deeper parts at about 500 m in contrast with that of May which is at about 300 m. During February at Ras Al Hamra Cape the deeper and stronger outflow is more affected by the steep topography slope leading to vortex stretching mechanism which causes it to meander as an "<i>S</i>" shape, while during May, weaker and shallower outflow is less influenced by bottom topography and so it continues along the boundary.