Both of Raman and infrared spectra of seven non-stoichiometry and threestoichiometry uranium oxides， including UO2, U3O7 and UO2+x（0＜x＜0.66）, are presented and discussed. The spectra of UO2+x in the stoichiometry range, U3O7 to U3O8, were first obtained and reported.　Three typical peaks were observed at 445, 578 and 1　150 cm-1 in the Raman spectrum of uranium dioxide. The intensities of the peaks at 578 and 1　151 cm-1 decrease quickly with increasing x value of UO2+x, and while x=0.19, the two peaks disappear. Such peaks can therefore be considered as a fin-gerprint of the quasi-perfect UO2 fluorite structure. The peak at 445 cm-1 tends to weaken, broaden and shift to higher wavenumber in more oxidised samples. When x=0.32, this peak is shifted to the 459 cm-1 and a weak peak at about 630 cm-1 appears. The two new peaks are typical of the tetragonal U3O7. While x≥0.39, the peak at 459 cm-1 further splits into separate components. Two peaks at 235 and 754 cm-1 appear for UO2.39 and are visible with increased intensity as the oxygen-uranium ratio is increased. And the Raman spectra of UO2+x are gradually close to U3O8 in the α-phase, which has an orthorhombic unit cell. But several strongest features of theα-U3O8 specturm at 333, 397, 483 and 805 cm-1 are still not outstanding even in UO2.60. The main feature of the UO2 infrared spectrum shows a very broad and strong adsorption band at 400～570 cm-1 and another feature is a weak adsorption peak at about 700 cm-1. The 400～570 cm-1 band undergoes a progressive splitting into two new peaks at ～421 and ～515 cm-1 through increasing incorporation of oxygen into UO2. The weak peak at about 700 cm-1 disappears and a new weak peak appears at about 645 cm-1. The three new peaks are the infrared absorption features of U3O7. An absorption peak at 744 cm-1 which is the strongest feature ofα-U3O8 infrared spectrum appears for UO2.39 and is visible with increased intensity in more oxidised samples. The peak at about 645 cm-1 still exists and 515 cm-1 peak has no further splitting into two new peaks at 485 and 535 cm-1 which also are the infrared absorption features of U3O8 in UO2.60. This indicates that UO2.60 is still in the transition period between tetragonal and orthorhombic phase of uranium oxide. A sequence of phase transitions occurs through increasing x value of UO2+x with different Raman and infrared features.It is easy to identify different uranium oxides by comparing of relative intensities and locations of their characteristic peaks.