Brown seaweed is an alginate-producing seaweed because of its high polysaccharide hydrocolloid content. Alginate is one type of hydrocolloid by organic polymers in water. This study aimed to obtain a suitable method in producing sodium alginate to produce a large yield. The research method includes the preparation of seaweed, extraction, and purification of alginate using EDTA, and testing the quality of the resulting alginate. The results showed that the yield of alginate produced in this study was 18.47-24.31%. The viscosity and water content test results showed that the alginate yield was 892 cps with an extraction time of 6 hours and 14.82% (w/v). Functional group analysis revealed a mannonate fingerprint region that indicated the absorption peak from alginate characteristics. The ash content test produced is in the range of 14.25%-26.57%. The pH of Na-alginate is in the range between 8-10. Water vapor transmission rate is ranged from 10.13-11.56 g/m2.hours to edible film application.