Binary ionic liquids (ILs), 1-butyl-3-methylimidazolium chloride and 1-H-3-methylimidazolium chloride, were developed to dissolve chitosan and cellulose and disperse multiwalled carbon nanotubes (MWCNTs). The resulting mixed paste could be used to prepare chitosan/cellulose/MWCNT composite membranes and fibers. Fourier transform infrared spectroscopy, wide-angle X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, tensile testing, and conductivity measurements were used to evaluate the structure and properties of the composite materials and the effect of the incorporation of MWCNTs at various loadings. The characterization results indicate that the incorporation of MWCNTs improved the comprehensive performances of the composite materials, and the best loading of MWCNTs was 4 wt %. This IL dissolution method is a green and feasible method for preparing chitosan/cellulose/MWCNT composite membranes and fibers and will provide beneficial references for the preparation of similar materials. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 128: 1193-1199, 2013