THE BIOSORPTION is an effective technique for the removal of uranium and thorium from some types of phosphate rocks of red sea area. In this study Cystoseira osmundacea, Palmaria elegans and Chondrus crispus, were used for the biosorption of uranium (U), and thorium (Th), from phosphates rocks in Egypt in Qusser and Safaga areas west red sea which characterized of shallow-water marine origin and mainly associated with sequences of white hard limestone, white chalk, yellow marls and hard cherts rocks. The obtained results showed that Cystoseira osmundacea, Palmaria elegans and Chondrus crispus have biosorption capacities of (81%, 89% and 90%), for U and (77%, 88% and 91%) for Th, respectively from phosphate of Safaga .and biosorption capacities of (81%, 84% and 89% ), for U and (79%, 81% and 88% ) for Th, respectively from phosphate of Qusser area. it is preferable to use Chondrus crispus on biosorption due to its high sorption capacity than the other two algae.