The silver nanoparticle is a silver metal in nano size which is currently widely applied in various fields, such as optics, electronics, biology, catalysts, health, food, and the environment. Silver nanoparticles can be synthesized by top-down and bottom-up methods. Bottom-up method can be done by reacting silver nitrate solution with plant extracts or known as green synthesis. This research is aimed to synthesis the silver nanoparticles using the methanolic extracts of Nephrolepis radicans ferns as bioreductor and testing their antioxidant activity. The characterization of silver nanoparticles synthesized was carried out using the UV and FTIR spectrophotometer. The antioxidant activity test was carried out using the DPPH method. The results showed that the silver nanoparticles synthesized had an average diameter of 19,194 nm. Based on the IR spectrum, the functional groups that played an important role in the process of synthesis of silver nanoparticles were  hydroxyl (OH), carbonyl (C = O) and ether (C-O). Synthesis of silver nanoparticles have antioxidant activity in the medium category with IC-50 of 126.45 ppm. Thus the silver nanoparticles synthesized had the potential to be developed as antioxidants.