In the present work, it was proposal a process for the extraction of sodium alginate, which was obtained from the brown macroalgae Macrocystis pyrifera collected in La Punta-Callao. The extraction process presented a yield of 12 % and the alginate obtained was characterized by FT-IR and 13C NMR techniques in solid state, which was compared with a commercial alginate. The evaluation of the presence of mannuronic and guluronic blocks has been carried out through the use of the 2nd derivative, obtaining characteristic signals at 894 cm-1 for C1-H α – L – guluronic in AlgM and at 885 cm-1 for C1-H anomeric region of the β-D-mannuronic in AlgC. Moreover, characteristic signals were assigned for the algae spectrum at 902 cm-1 and at 812 cm-1 corresponding to vibrations of the α – L – guluronic blocks. By 13C NMR in solid state, a characteristic peak was obtained at 102.4 ppm for Alg...