Eco-Friendly biogenic synthesis of gold and iron oxide (Au/Fe3O4) Magnetic nanoparticles (MNPs) using Lepidagathis cristata (LC) leaf extract act as capping and reducing agent. The prepared MNPs was characterized by different analytical techniques such as UV-Vis, FT-IR, XRD, TEM, VSM and BET adsorption-desorption methods. The XRD revealed the formation of LC/Au/Fe3O4 MNPs with crystallite size of about~30 nm. The synthesized LC/Au/Fe3O4 MNPs were found to be ferromagnetic nature, which was confirmed by vibrating sample magnetometer (VSM) at room temperature. Besides, the prepared composite exhibits high specific surface area of 23.6 m2g-1. As well as, the LC/Au/Fe3O4 MNPs showed a good catalytic nature for the degradation of Rhodamine-B (Rh-B) in the presence of Sodium borohydride (NaBH4) in aqueous solution.