Niobium oxide amorphous films were deposited on silicon substrates at temperatures ranging from 200-300 ℃ by heating a pure niobium foil in a rough vacuum. The films were amorphous in structure and with morphology of vertically aligned nanocolumniations. This structure after anealing is of interesting photoluminescence property in the visible light range. The curve of emission intensity with annealing temperature of films was given. The mechanism for this photoluminescence (PL) behavior of the amorphous niobium oxide films was also investigated and discussed;the changed power PL experiment having supported the result forcefully.