Abstract: This Paper ai ms at investigating the photochemical reduction to produce U(Ⅳ) in the organic phase of TBP-Kerosene-UO2(NO3)2-HNO3 System. The optimum conditions for producing U(Ⅳ) are: T-20℃; HNO3=0.8-1.25M, UO2 2+>0.2M in the initial aqueous phase; TBP=30% in the organic solvent. Under such conditions, the concentration of U(Ⅳ) in the organic phase, which is exposed to a mercury lamp with 125W for 150 min is-23g/l. The yields of Uranium(Ⅳ) with washed solvents by different methods and with recovered solvents by different cleaning methods are compared.