Abstract: Cellulose was modified with citric acid in high temperature. Investigations of its absorption of heavy metal ions (such as Pb2+ and Cd2+) showed that modified cellulose in conditions 120°C and 12 h and in mass ratio of cellulose :citric acid=1:3 had highest absorption capacity. Absorption capacity of modified cellulose increased in accordance with increase of concentrations of ions. Structure of modified cellulose was confirmed by IR spectra and SEM pictures.