Natural polysaccharides with grafting of vinyl monomers and then compounding with nanofillers become a preferred method to derive novel nanocomposites because of its unique environmental and economic advantages.In present work, hydrogel nanocomposites were synthesized by free radical polymerization of carboxymethyl cellulose (CMC), acrylic acid (AA) and hydrophilic nanoparticles (cellulose nanocrystals and nano-TiO2) using ammonium persulfate (APS) as initiator and N, N-methylenebisacrylamide (MBA) as crosslinker.Fourier transform infrared spectroscopy (FTIR) proved that AA was successfully grafted onto CMC backbone and nanoparticles participated in gelation process.Transmission electron microscopy (TEM) and field emission scanning electron microscope (FESEM) analyses shown that nanofillers were uniformly dispersed in the CMC-g-AA matrix.The swelling properties, dye adsorption behavior, thermal stability and mechanical strength of the formed gels were investigated.A possible mechanism concerning the interface interaction of the organic/inorganic and organic/organic constituents for forming hydrogels were proposed.CNC were not only a reinforcing agent for hydrogels, but also acted as a multifunctional crosslinker for gelation.Incorporation of CNC into the cellulosic hydrogels led to an increase in the compressive modulus of final nanocomposites, but a corresponding decrease in the swelling ratio.However, the addition of nano-TiO2 enabled an enhancement in the thermal stability of the final nanocomposites.Both of them induce an obvious decrease in amount of cation dye adsorption.The remarkable pH-sensitivity of the hydrogel nanocomposite was also evaluated.