Abstract: Variations of microscopic morphology and oxidation products of metal uranium were in-situ investigated from room temperature to 400℃ in air with micro laser Raman spectroscopy(LRS), Fourier transform infrared(FT-IR) spectroscopy, and scanning Kelvin probe force microscopy(SKPFM), respectively. The results show that the surface microscopic morphology of uranium show pockety global knaggy in room temperature. The surface potential of uranium is higher around the granules and in the hollows, and dot corrosion takes place more easily on the surface of uranium. Furthermore, the surface of uranium can adsorb and subsequently react with oxygen, water and carbon dioxide in air, forming uranium dioxide, uranyl compounds, carbonate, etc.. Heated up under different temperature, some active corroded light spots appear on the surface of uranium at the beginning of heating, and they get together and grow up gradually. The major corrosion product is uranium dioxide (UO₂) that begins to change into triuranium octoxide (U₃O₈) above approximate 260℃.