The electrochemical behavior of molybdenum electrode in acetic, formic and oxalic acid solutions is studied. The effect of immersion time, composition medium, applied voltage, applied current density and scanning rate is investigated using potentiodynamic, potentiostatic and galvanostatic polarization measurements. The stability of the oxide film formed on Mo electrode is affected by both the formation medium and the applied potential. In 0.5N oxalic acid, the critical applied voltage below which the current start to oscillate is equal to -80 mV. The rate of dissolution of anodic oxide film formed on Mo in oxalic acid is very rapid compared with that formed in acetic and formic acids. Also in oxalic acid solutions Mo is notably affected by applied current density in which reciprocal capacitance, C_s^-1, decrease with increasing applied current density. On the contrary in acetic and formic acids Mo did not affect. In acetic acid solution, the time of anodization has little or no effect on the dissolution process.