Abstract: In the present study, the phytochemicals and anti-oxidant ability rich marine mangrove plant Rhizophora mucronata (R. mucronata) was evaluated. The UV-bio spectrometer result of O.D value of phenolic content was shown 0.986 as well as flavonoid content were shown 0.994 at 100 itg/mL concentration. The high yields of phenol and flavonoid contents were observed compared with standard gallic acid and rutin. Concisely, the more phenols and flavonoids and some bioactive derivatives were clearly exhibited by LC-MS scanning report. In addition, the anti-oxidant activity result shown with 85 % and DPPH scaveng-ing assay result shown 66% in crude extract of R. mucronata were observed and it was very higher than the rate of standard gallic acid and ascorbic acid. Further, the liquid-liquid extraction of available bioac-tive compounds were purified and shown excellent anti-bacterial activity against multi drug resistant bacteria. The anti-microbial activity result indicated that the 250 itg/mL of R. mucronata extract was shown 24 and 26 mm zone of inhibition against K. pneumoniae and A. baumannii. Then, the concentration dependent inhibition of R. mucronata extract was shown against both the tested pathogens and 250 itg/m concentrations was fixed as a minimum inhibition concentration range. Finally, the induction of outer cellular layer morphology effect and damaged size and shapes of the R. mucronata extract was shown against K. pneumoniae and A. baumannii. Altogether, the present study results were deliberately recom-mended that the R. mucronata extract as potential anti-oxidant and anti-bacterial agent. Hence, the natural marine mangrove plant R. mucronata is the safe, eco-friendly, low cost source for discovery of potential drug against various infections.(c) 2023 The Authors. Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).