A graphite paste modified electrodes with Cr2O3 nanoparticles and polyaniline nanocomposite were prepared to study the electrochemical behavior of urea in 1M KOH solution. A co-precipitation simple method was utilized to synthesis the Cr2O3 nanoparticles and chemical polymerization was used to prepare polyaniline (PANI). The modified electrodes under study were prepared by mixing of graphite powder with Cr2O3 nanoparticles and PANI in a ratio of (1/4 w/w). The electrodes were characterized by X-ray diffraction, field emission scanning electron microscopy, cyclic voltammetry and differential pulse voltammetry. The electrocatalytic activity of the electrodes toward urea was investigated. The results indicated that the Cr2O3/graphite (Cr-G) electrode was more sensitive to urea than PANI /graphite (P-G) or PANI/Cr2O3/graphite (P-Cr-G) electrodes. The cyclic voltammetry method was used to determine the linear range and limit detection. Accordingly, the modified electrode (Cr-G) showed a linear range of (0.001 - 0.040) mM and a detection limit was 0.00637 mM. Moreover, the kinetic characteristics of urea, like transfer coefficient and the rate constant, were examined in an alkaline media.