Radish (Raphanus sativus L.) root is commonly used as flavor enhancing additive or side dish. Previous research revealed the presence of active compound in which could inhibit bacterial growth. Thus, a research concerning natural antibacterial for fish products that are categorized as high-risk food being contaminated by spoilage bacteria (Pseudomonas aeruginosa, Bacillus cereus, dan Staphylococcus aureus) was done. Radish root extraction was made by using ethyl acetate (semi polar) for 3 days. Well diffusion was performed using 4 extract concentration (10, 20, 30, dan 40% (w/v)) againts three fish spoilage bacteria. Based on our results, 30% concentration was the best concentration which inhibit more than 10 mm in inhibition zone with MIC and MBC. The scores were of 0.06% and 0.24% (P. aeruginosa), 0.13% and 0.50% (S. aureus), and 0.12% and 0.48% (B. cereus). Moreover, based on stability test against heating temperature showed that this extract concentrationwas more stable in 80°C with duration times for 5 minutes and pH 3 which resulting the lowest inhibition zone reduction compares to control extract. Radish extract was categorized as low toxic compound (LC50 = 839.52 ppm) functioning in antibacterial compound containing major antibacterial compound (bis(2-ethylhexyl) phthalate, 1,2-benzenedicarboxylic acid, 9,12,15-octadecatrienoic acid), fatty acid (n-hexadecanoic acid, butanedioic acid), carboxylic acid (isobutyric acid, malic acid, oleic acid), and minor antibacterial compound (n-Hydroxymethylacetamide, 2,4-bis(1,1-dimethylethyl), 2,4-pentanedione,2-Cyclohexen-1-one, hydrazine, cyclohexene oxide, gamma-sitosterol).