A new sensor for the determination of nicotine is proposed based on the reduction of Cu(II)-nicotine complex at MWCNT modified carbon paste electrode. In borate buffer (pH 7.0) the reduction peak of Cu(II)-nicotine complex was observed at-0.05V (versus Ag/AgCl). The increment of peak current obtained by deducting the reduction peak current of the Cu(II)-nicotine complex was rectilinear with nicotine concentration in the range of 0.05-30.0n g mL(-1), with a detection limit of 0.01ng/mL(-1). The method was applied for the sensitive quantification of nicotine in real samples with the satisfactory results.