The 2-hydroxypropyltrimethyl ammonium chloride chitosan (HACC)-grafted multiwalled carbon nanotubes (MWCNTs) composite (HACC-MWCNTs) was prepared via covalently grafting HACC onto the surfaces of MWCNT. The properties and morphology of the resulting materials were monitored by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The results of FTIR and TGA indicated that the interaction between MWCNT and HACC was grafting through covalent links. TEM and SEM images confirmed MWCNT stained with an extra phase after the grafting process that was presumed to come from HACC. The dispersion of MWCNT in H2O was improved after the grafting of HACC,which was in agreement with the positive charge of HACC-MWCNT at any pH value. The electrochemical properties of HACC-MWCNT were investigated by cyclic voltammetry (CV). The dramatic improvement in the electrostatic interactions between HACC-MWCNT/electrode and anionic complexes was distinguished from the response of chitosan-MWCNT/electrode and non-modified electrode. According to the experimental results, the HACC-MWCNT had a possibility to serve as a novel material for innovative anionic sensor.