Mangrove is a coastal plant that has rich benefits. This research aimed to investigate X. granatum leaves extract as a mosquito larva eradicator and find the antibacterial activities of its bacteria. The eradicator test was done for 24 and 48 hours. As many as 10 pieces of cups, filled with 50 ppm, 100 ppm, 250 ppm, 500 ppm, and 1000 ppm of X. granatum leaves extract. Each cup contains 10 mosquitoes (Aedes aegypti). Probit LC50 test was carried out from X. granatum leaves extract and an antibacterial test was carried out by isolating bacteria from X. granatum leaves. The survival rate percentage of larvae in X. granatum leaves extract, the highest was 50% at 24 and 48 hours and the lowest was 0% at 48 hours. The result of the probit test shows 426,618 mg/L at 24 hours and 100,193 mg/L at 48 hours, categorized as a toxic compound. There were a total of 7 pure isolates obtained. Antibacterial tests showed the antibacterial activity of isolates against Staphylococcus aureus, Vibrio harveyii, and Vibrio alginolyticus, with the result being 3 isolates (XGL1, XGL2, and XGL3), 2 isolates (XGL6 and XGL7), and 4 isolates (XGL2, XGL3, XGL6, and XGL7). Based on the results, 1000 ppm X. granatum leaves extract has the potential as a mosquito larva eradicant or Phyto-insecticide. In addition, there were symbiont bacteria in X. granatum leaves that were potentially used as larva eradicant.