The biosorption of Pb(II) ionsfrom aqueous solutions using Papaya (Carica papaya L) leavesand Petai (Parkia speciosa Hassk) peels activated with HNO3 0,01 mol/Lwas studied in batch method. The optimum conditions forbiosorption of Pb(II) ions at pH 4.0, initial concentration 5400 mg/L using Papaya leaves and pH 5.0, initial concentration 590 mg/L using Petai peels. While optimum contact time 15 min, biosorbent mass 0.1 g for both biosorbent with biosorption capasity (Q) of Pb(II) ions at 284.35 mg/g and 36.01 mg/grespectively. The biosorpstion data follow Langmuir isotherm models by using Petai peels and follow Freundlich isotherm by using Papaya leaves. The concentration Pb(II) ions after biosorption were measured by using Atomic AbsorptionSpectrofotometer (AAS), while the characterisation biosorbent performed using Scanning Electron Microscope (SEM) and Fourier Transform Infra Red Spectroscopy (FTIR). FTIR analysis showed the hydroxyl and carboxyl functional groups have a role in the biosorption process of Pb(II) ions.