[en] The potentiodynamic polarization studies were carried out on Zr based bulk amorphous alloy Zr₅₇Cu_15.4Ni_12.6Al₁₀Nb₅ and Zr₅₉Cu₂₀Ni₈Al₁₀Ti₃ in solutions of 1 M, 6 M and 11.5 M HNO₃ aqueous media at room temperature. As received specimens of Zr₅₇Cu_15.4Ni_12.6Al₁₀Nb₅ (5 mm diameter rod) and Zr₅₉Cu₂₀Ni₈Al₁₀Ti₃ (3 mm diameter rod) were polished with SiC paper before testing them for potentiodynamic polarization studies. The amorphous nature of the specimens was checked by X-ray diffraction. The bulk amorphous alloy Zr₅₉Cu₂₀Ni₈Al₁₀Ti₃ shows the better corrosion resistance than Zr₅₇Cu_15.4Ni_12.6Al₁₀Nb₅ alloy in the aqueous HNO₃ media as the value of the corrosion current density (I_corr) for Zr₅₇Cu_15.4Ni_12.6Al₁₀Nb₅ alloy were found to be more than Zr₅₉Cu₂₀Ni₈Al₁₀Ti₃ alloy in aqueous HNO₃ media. The improved corrosion resistance of Zr₅₉Cu₂₀Ni₈Al₁₀Ti₃ alloy is possibly due to the presence of Ti and formation of TiO₂ during anodic oxidation. Both Zr based bulk amorphous alloys shows wider passive range at lower concentration of nitric acid and the passive region gets narrowed down with the increase in concentration. A comparison of data obtained from both the Zr-based bulk amorphous alloys is made and results are discussed in the paper. (author)