Abstract: Sodium alginate as a natural polymer has been widely used in various research fields. This paper reviewed systematically recent advances in several extraction technologies in sodium alginate, mainly including acid coagulation-acidification, calcium coagulation-acidification, calcium coagulation-ion exchange, enzymolysis, ultrafiltration. The advantages and shortcomings of these techniques were comparatively analyzed. On this basis, the functionalization of hydroxyl group and carboxyl group in sodium alginate were summarized, and the potential application of sodium alginate derivative was also discussed. Furthermore, we present the suggestions and outlooks concerning on the further development directions towards key researches based on the existing problems in the current extraction and functionalization of sodium alginate.