提出了在ｐＨ８５０条件下，Ｃｕ（Ⅱ）与铜试剂（ＤＤＴＣ）生成有色配合物，与强碱性阴离子树脂交换吸附，树脂相光度法测定痕量Ｃｕ（Ⅱ）的新方法。结果表明，有色配合物树脂相的最大吸收波长为４２０ｎｍ，Ｃｕ（Ⅱ）含量在０～２０ｍｇ·Ｌ－１范围内符合Ｂｅｅｒ定律，表观摩尔吸光系数为５１×１０４Ｌ·ｍｏｌ－１·ｃｍ１。用于水样中痕量Ｃｕ（Ⅱ）的测定，相对标准偏差小于２３％，加标回收率９７％～１０２％。 A new method was developed for the determination of trace Cu (Ⅱ) with Cu (Ⅱ) and copper reagent (DDTC) under pH850 conditions by exchange adsorption with strongly basic anion resin and resin phase spectrophotometry. The results showed that the maximum absorption wavelength of the colored resin phase was 420 nm and the Beer’s law was obeyed in the range of 0 ~ 20 mg · L-1 for Cu (Ⅱ). The apparent molar absorptivity was 51 × 104L · mol- 1 · cm-1. For the determination of trace Cu (Ⅱ) in water samples, the relative standard deviation was less than 2.3% and the recovery was 97% -102%.