Abstract: The photochemical reaction in nitric acid solution containing Pu(III), Fe(II) and N2H5+ is studied to explore its possible application in spent nuclear fuel reprocessing. A GGH-120 Hg lamp is used as the light source. The effects of various factors on the photo-reaction are investigated.Experimental results show that Fe(II), N2H5+ and Pu(III) are oxidized rapidly and completely during the course of irradiation. The initial rate of photooxidation of Fe(II) and N2H5+ is proportional to the power of light, Fe(II) and N2H5+0.5 respectively. In the nitric acid solution, HNO2 is produced during the irradiation, but in the system containing N2H5+ with or without Fe(II), HNO2 is not detected until the complete oxidation of Fe(II) and N2H5+.Photooxidation of Pu(III) occurs via the following three stages: (1) slow oxidation of Pu(III) to Pu(IV) .The initial rate of photooxidation is proportional to Pu(III),increases with the increase of NO3-andH +, and decreases with the increase of UO22+; (2) rapid oxidation of Pu(III) to Pu(IV);(3) disproportionation of Pu(IV) to Pu(III) and Pu(VI) .It is observed that the yield of Pu(VI) increases with the increase of HNO3, but the yield is considerably reduced when Fe(III) is present in the system.