Marine algae are the most important source of non-animal sulphated polysaccharides which possess important pharmacological activities such as anticoagulant, antioxidant, anti-inflammatory, antiviral, antibacterial agents. Therefore, marine algae derived sulphated polysaccharides have great potential to be further developed as medicinal products. Marine macroalgae were collected seasonally for one year (September 2013 to August 2014) from the intertidal zone of site I: Ras El-Adabiya whichlocated on the western shore of Suez Bay and site II: Ras Sedr which located north–east of the Gulf of Suez. The purpose of this study was to extract sulphated polysaccharides from marine macroalgae (Ulva lactuca, Codium dwarkense, Hypnea cornuta, Hormophysa triquetra, Sargassum denticulatum and Cystoseira  myrica) by two different methods (hot and cold water extracts) and chemical analysis also done ( protein content, total sugar , sulphate content , sulfer  and  nitrogen  and  uronic acid).  The results of thephysico-chemical parameters for sea water samples showed that temp ranged between 15-30 °C, pH 7.8-8.7, salinity 38-42 ‰ , DO 6-7 mg/L, NO₃ 0.021-4.6 mg/L,NO₂ 0.004 -0.032 mg/L, NH₄ 0.019-0.3mg/L and PO₄ 0.005-0.015 mg/L. The potential of use sulphated polysaccharides as natural anticoagulant was tested by the activated partial thromboplastin time  (APTT) and the prothrombin time (PT) tests. The results showed that higher blood anticoagulant activity of SPs is proportional to the carbohydrate and sulphate contents and inversely proportional to the protein and uronic acid contents. So, The significant highest value of prothrombin time was 26.50±0.10 sec at conc. of 20% SPs cold extract from the brown alga Hormophysa triquetra, while the lowest value was 1.13±0.06 sec at conc. of 5%  SPs hot extract of the red alga Hypnea  cornuta. Also, the results  indicated that the highest value of activated partial thromboplastintime 42.20±0.10 sec  was recorded atconc. of 20%   SPs cold extract from  the brown alga Hormophysa triquetra, On the other hand, the lowest value 5.63±0.25 sec was recorded at conc. of 5%  SPs hot extract from the red alga  Hypnea  cornuta .