本文报道了新显色剂２－（４－安替比林偶氮）－４－甲基－５－氨基苯膦酸的合成及其在分析上的应用。试验结果表明，在强酸性溶液中，试剂仅与钯形成络合比为１：２的红色可溶性的稳定配合物，其最大吸收波长为５２５ｎｍ，表现摩尔吸光系数为５，５×１０￣４Ｌ·ｍｏｌ￣－１·ｃｍ￣－１，钯浓度在０～３５μｇ／２５ｍｌ范围内遵守比尔定律。试剂对钯具有高选择性，所拟方法简便、快速，不经分离即可直接进行含钯试样的分析，结果满意。 This paper reports the synthesis and application of 2- (4-antipyrine azo) -4-methyl-5-aminophenylphosphonic acid, a new chromogenic reagent. The experimental results show that the red stable complex with the complex ratio of 1: 2 is formed only with palladium in strong acid solution, the maximum absorption wavelength is 525 nm, the molar absorptivity is 5 × 10 4 L · mol ~ -1 · cm ~ -1, the Beer’s law is obeyed in the range of 0 ~ 35μg / 25ml. Reagents of palladium with high selectivity, the proposed method is simple, fast, without separation can be directly analyzed with palladium-containing samples, the results are satisfactory.