2-Chlorobenzoyl ferrocene (2CBF) was synthesized and used to construct a modified-carbon nanotube paste electrode. The electro-oxidation of isoproterenol at the surface of the modified electrode was studied using cyclic voltammetry (CV), chronoamperometry (CHA) and square wave voltammetry (SWV). Under the optimized conditions, the square wave voltammetric peak currents of isoproterenol increased linearly with isoproterenol concentration in the range of 2.5×10-7 to 8.0×10−5 M and detection limit of 9.0×10-8 M was obtained for isoproterenol. Finally this modified electrode was used for determination of isoproterenol in real samples.