Shock-recovery experiments on Nb 2O 5 powder specimens are made in pressure ranges up to 50 GPa using the gun method. "NbO 2" with the rutile structure is formed above about 40 GPa when an open recovery fixture is used. The tetragonal unit cell dimensions are measured to be a = 4.784(2) Å, c = 3.029(2) Å, and V = 69.34(6) Å 3. The metal-to-oxygen ratio is determined to be Nb 0.94O 2 by means of thermogravimetry. A comparative study is made on the shock reduction behavior of Nb 2O 5 and Ta 2O 5.