<b>Background and Objective:</b> Sources of antibiotics that are cheap and easy to obtain are by exploiting endophytic microbes from betel plants because betel plant extracts are known to produce anti-microbial compounds. This research aimed to obtain isolates of antibiotic producer endophilic bacteria from betel leaves in Jambi city forest park. <b>Materials and Methods:</b> This research consists of several stages, sterilization of the collected betel leaf surface, isolation and purification of endophytic bacterial isolates, screening of antibiotic-producing bacteria and characterization of endophytic bacteria. <b>Results:</b> There were 3 types of betel plants found in the area, namely: <i>Piper betle</i> L. (green betel), <i>Piper crocatum</i> Ruiz and Pav (red betel) and <i>Piper aduncum</i> L. (forest betel). In red betel leaves, 9 types of endophytic bacterial isolates were obtained, while only 1 isolate was found in each green betel and forest betel leaf. Of these 11 isolates, 9 of them produced antibiotics. However, only 6 isolates were potential since they had a halo zone bigger than 10 mm for <i>E. coli</i> (gram-negative) and <i>S. aureus</i> (gram-positive). Among these 6 isolates, 5 isolates were from red leaves with isolate codes of BESKJ-m2, BESHKJ-m3, BESHKJ-m4, BESHKJ-m5, BESHKJ-m6 and 1 isolate from forest betel leaves with code of BESHKJ-s1. <b>Conclusion:</b> From the control positive test using chloramphenicol, it was known that the endophilic bacteria had a broad spectrum. The bacterial colonies were white and had an elevation on the surface of the media with flat to irregular margins. The catalase and Gram stain tests showed that the bacteria were Gram-positive.
Keywords: Exploration; antibiotics; bacteria; betel leaf; endophytic; fermentation; forest park.