In this research, graphene oxide (GO) was functionalized by tannic acid to produce GO-TA and fabricate a novel functionalized graphene oxide/ polyacrylonitrile (PAN) nanofibrous as an adsorbent in order to remove two hazardous heavy metals from aqueous solutions. The results showed that the composite adsorbent can properly adsorb Pb2+ and Cd2+ metal cations, due to having the numerous potential active sites. The optimum conditions for 97.37% of Pb2+ and 94.28% of Cd2+ ions removal were meanly obtained at pH of 6.3, nanoparticles weight percentage of 4.26 wt.%, metal ions concentration of 35.74 ppm and contact time of 70.5 min. The maximum adsorption capacities for lead and cadmium ions.were found at 344.83 and 312.5 mg/g, respectively.