en Biochemistry Biochemistry پژوهشي Orginal research papers More than 3000 MT of <em>Sargassum</em> <em>illicifolium </em>,annually washed-up from the Oman Sea (Sistan and Baluchestan province). , According to the estimates of the Iranian Fisheries Sciences Researchinstitiute.The brown seaweed biomass has been considered as one of the best free sources for production of sodium alginate. A key objective of this study was to determine the biochemical composition of <em>Sargassum illicifolium</em> collected from Chabahar Bay in November 2018 and to understand the economic potential and cost drivers of sodium alginate on basis of the present macroalgae. Alginates were purified by re-precipitation with ethanol and characterized by infrared spectroscopy. The results showed that the Chabahar <em>Sargassum</em> was characterized by total protein (TP), total lipid (TL) and carbohydrate as 9.8&plusmn;0.8%, 4.4&plusmn;0.2% and 33.2&plusmn;4.1% dry weight, respectively. The ash content contained 41.6&plusmn;2.3% DW. Moreover, the n-6/n-3 ratio was 2.62 and total essential amino acids and total minerals were 29.1&plusmn;0.2&nbsp;mg g^-1 DW and 102. 2&plusmn;0.6&nbsp;mg g^-1DW, respectively. sodium alginate of <em>Sargassum</em> <em>illicifolium</em> was found to be high as 28.2% purification with molecular weight of 8.06&times;105 g mol^-1. Its total production price was evaluated 7.66 $ per kg sodium alginate, which is much cheaper than existing ones on the Iranian market.<br> &nbsp; Alginic acid yield, Macro algae, Purification, Proximate composition, Chabahar coast, Sea of Oman 1 12 http://jifro.ir/browse.php?a_code=A-10-46-11&slc_lang=en&sid=1 M. Hafezieh jhafezieh@yahoo.com 100319475328460039156 100319475328460039156 Yes IFSRI, AREEO A.M. Abkenar aliabkenar@gmail.com 100319475328460039157 100319475328460039157 No Chabahar Azad University S. Jadgal Salimjadgal@yahoo.com 100319475328460039158 100319475328460039158 No IFSRI,AREEO A. Azhdari a_arzhan@yahoo.com 100319475328460039159 100319475328460039159 No IFSRI,AREEO