Abstract: The previous method with m-NPFand CTMABas reagents for spe-ctrophotometric determination of microamount of zirconium has been developed for simultaneous determination of microamount of zirconium and hafnium in this work. The determination is based on the calculation by CPA-M-atrix method. The optimum experimental conditions for the determination have been established and ten mixed samples with arbitrary proportions of Zr and Hf wereexamined by this method with very satisfactory results.Meantime the problem of selecting wavelengths which is the key to the determination is discussed thoroughly and concepts of "correlation wavelengths" and "correlation components" are proposed in this paper.

Key words: Spectrophotometric determination of zirconium and hafnium, CPA-Matrix calculation, m-Nitrophenylfluorone.