The purpose of this study is to highlight on the ability of the alga Ulva fasciata to accumulate some organic pollutants (polycyclic aromatic hydrocarbons :PAHS, polychlorinated biphenyls: PCBs). The samples were collected from three sites at the Syrian coast during 2011. The result of this study revealed the ability of alga to accumulate significantly the PAHs and their concentrations ranged from 30.52 to 72.7 ng/g dw, While the PCBs concentrations were less, it ranged between 6.00 and 24.01 ng/g dw. The highest concentration of PAHs was observed at the Dirasat site, while the highest concentration of the PCBs found at the Cornish of Jablah. The logarithm bioconcentration factors (log BCF) of the aromatic compounds with three aromatic rings were close to the logarithm octanol/water partitioning coefficients (log Kow ), unlike the compounds with higher rings, where log BCF were obviously less than corresponding log Kow. The log BCF values of PCBs increased with increasing chlorine atoms (2 - 6 atoms) , while no increasing was observed for components that contain 7 to 8 chlorine atoms