Abstract: In this paper,a new method,flow injection analysis with ion exchanger and spectrophotometric detector is reported for determination of plutonium in irradiated uranium fuel elements.A device is fixed in which a column is filled with Y-701 fine particle anion exchange resin. An automatic sample taken and a flow spectrophotometric detector are included. In this work a new efficient eluant is used. A good peak of plutonium without tail is given by the eluant. In case the ratio of Pu to U is 3×10-3 and concentration of plutonium is about 3μg/ml,the relative standard deviation is better than 5 %. It takes about 25 minutes to analyse one sample. The procedure is simple and fast.