Graphene oxide nanoparticles was synthesized by modified Hummer’s method and polymerized by aniline. PES/modified graphene oxide nanocomposite membrane was prepared by phase inversion method and using 0.25 wt.% of modified graphene oxide nanoparticles. SEM, water contact angle, bulk porosity, water permeability and lead ion removal tests were employed to evaluate membrane characteristics and performance. Removal of lead ion from water was conducted under different solution pHs (3.5 and 6.0) to probe the effect of solution conditions on the membrane efficiency. Results showed that addition of only 0.25 wt.% of modified graphene oxide nanoparticles improved remarkably the lead removal of PES membrane from 19 to 98%. Moreover, increment the solution pH from 3.5 to 6.0 increased the membrane performance from 62 to 98 %, respectively