Uraninite has been found in tungsten bearing quartz veins, granite and greisen in Shirenzhang Tungsten Deposit. It is shown by identification of rock mineral and Scanning electron microscopy, energy spectrum analysis (EDS) that uraninite and thorite (including thorium containing uraninite, uranothorites, uranium containing thorite and thorianite) usually form the isomorphous series, and have paragenetic relation with pyrite, xenotime, zircon, monazite and so on. The uraninite’s composition have variations along with different veins and levels, can form the growth zoning result from instability inside minerals; The UO2 content of uraninite is increase from the greisen to the quartz vein and higher in relatively big particles of uraninite than tiny ones. There is higher of nad lower of in the marginal of uraninite mineral, but it is exactly the opposite in the centre of uraninite mineral. X ray diffraction (XRD) analysis and electron probe confirms the presence of uraninite, and its main component is UO2. Along with the enhancement of hydrothermal activity and the growing of mineral particles, uraninite compositions become pure and uranium dioxide has an increasing trend; during epigenetic change of the uranium particle rich in impurities can be dissolved out and formed pyrite’s rim formation at the edge of uraninite. The uraninite age tested by electron microprobe is approximately from 151 to 157 Ma, which are consistent with the age of tungsten mineralization in this area and uranium mineralization in southern China. They are belong to the occurrence of the same ore forming hydrothermal activity of metallogenic outbreak stage during Yanshan epoch, and it is important significance on searching for uranium resources inside and around tungsten deposit in the region.