Abstract: In the medium of hydrochloric acid,uranium(Ⅳ) and uranium(Ⅵ) can completely colored with chlorophosphonazo Ⅲ. The linear range is 0～70 and 0～60 μg in a sample with a volume of 25 mL for U(Ⅵ) and U(Ⅳ), respectively. The complexes have good additive property in the range of 620～710 nm. Their molar absorptivity are bigger than 10 4 L·mol -1 ·cm -1. Linear combination of multi wavelength data method is applied to do with the calculation.The results show that the method is simple,rapid,sensitive and accurate.