Abstract: Seaweed Gymnogongrus sp is endemic to the Maluku region, with the local name "vegetable coral" which usually begins to grow early in the east (April) season along the south coast of Ambon island (Hutumuri - Mahia) and is harvested from July to September. People usually consume them as side dishes. Seaweed can be explored as a natural preservative. In order to preserve fresh food business, especially fish in a sustainable manner using natural preservatives containing bioactive components as antibacterial. To obtain the content of organic compounds from dried plants is to extract the continuous connecting powder of the starting material using a hexane solvent series of solvents alternately, ranging from lowest to highest polarity level or from non polar (Hexane) to produce hexane 1, semi polar extract (Ethyl acetate ) to polar (Methanol). In this study also tried the opposite of polar, semi polar and non polar yielding hexane 2 extract. In this study hexane 1 and hexane 2 extracts are used as test extracts. The purpose of this research is to know the rendement and power of antibacterial of hexane extract from seaweed vegetable type Gymnogongrus sp. The results showed that the yield of hexane 1 extract (0.149%) was higher than hexane 2 extract (0.108%). The antibacterial power to Escherichia coli, Salmonella thypi and Bacillus subtilis from n-hexane 2 extracts is, 42.33; 37.50 and 20.83 mm better when compared with n-hexane 1 extract and control (DMSO) with the result of drag zone diameter respectively: 26.00; 39.33 and 20.17 mm and 11.00; 19.50 and 13.00 mm.