The homogeneous electrocatalytic oxidation of hydrazine (HZ) has been studied by indigocarmine (IND) as a mediator at the surface of TiO2 nanoparticles modified carbon paste electrode (TNMCPE).Cyclic voltammetry was used to study the electrochemical behavior of IND at different scan rates.The voltammetric response of the modified electrode was linear against the concentration of HZ in the ranges of 3.0 × 10-8-7.0 × 10 -6 mol/L with differential pulse voltammetry method.The detection limit (3σ) was determined as 27.3 nmoL/L.To evaluate the applicability of the proposed method to real samples,the modified CPE was applied to the determination of HZ in water samples.