Using the235U induced fission track method and microscopic annalysis, the brannerite —uraninite —coffinite —pitchblende micro assemblage in ore bearing cryptoexplosive breccia from No 6722 uranium deposit is firstly determined. This mineral micro assemblage distributing in a micro limited area (1cm2, polished thin section) were formed from a physic chemical system. According to the stability fields of uranium minerals synthesized in the UO2—TiO2—H2O system, it is confirmed that the brannerite—urannerite —coffinite—pitchblende micro assemblage of No 6722 uranium deposit was formed within the range of 250~350℃ and attributed to middle—high hydrothermal genesis.