Seaweeds are one of the most abundant forms of biodiversity in Indonesian waters. Ulva reticulata is a potential seaweed. U. reticulata was developed as a salt preparation since it contains complete amino acids, especially glutamate and aspartic acid. These two amino acids contribute to the salty and umami flavors. Therefore, the objective of this study was to assess the chemical composition, water activity, and amino acid profile of U. reticulata seaweed salt preparations. This study consisted of three treatments, including treatment without the addition of maltodextrin (P0), addition of 2% maltodextrin (P1), and addition of 4% maltodextrin (P2), which was repeated three times. Data were analyzed descriptively using Microsoft Excel and all data were expressed as mean. The results showed that U. reticulata seaweed salt has an average moisture, ash, fat, protein, and carbohydrate content of 4.60-6.83%, 29.39-62.15%, 0.96-1.45%, 2.03-3.87%, 26.17-61.16%, respectively. Furthermore, the resulting water activity values averaged 0.33-0.39. For the amino acid profile, 16 types of amino acids were confirmed and among the highest values were the types of amino acids alanine, aspartic acid, glycine, glutamic acid, leucine and serine with respective values of 1639.40-1940.56ppm, 1982.17-2104.82ppm, 2199.16-2276.03ppm, 1872.09-2215.11ppm, 1020.70-1099.97ppm, 2052.42-2620.07ppm. These results indicate that the U. reticulata seaweed salt produced has a long shelf life and contains amino acid compounds that contribute to the salty and umami flavor.