In this paper, a glassy carbon electrode was modified by nanocomposite of chitosan, MWCNTs and ionic liquid and used for electrooxidation study of cetirizine and it's sensing using differential pulse adsorptive stripping voltammetry (DPAdSV). Impedance spectroscopy, cyclic voltammetry (CV) and scanning electron microscopy (SEM) were used for electrode modification process. Correction of the electrode surface increased its response to target and improved the linear dynamic range (40 nM-480 mu M) and limit of detection 8 nM. The stability, reproducibility, and repeatability of the nanocomposite modified electrode were considered and it was used for the monitoring of cetirizine in serum and tablet as real samples.