用固体酸五氧化二铌作酯化催化剂，由苯酐和２－乙基己醇制备了邻苯二甲酸二（２－乙基己酯）（ＤＯＰ）。反应先快速生成中间产物邻苯二甲酸单（２－乙基己酯），然后再酯化成双酯ＤＯＰ。由单酯转化成双酯的反应为典型的二级反应，测定了二级反应的速率常数和活化能。研究了催化剂的循环使用，探讨了反应时间、反应温度和催化剂用量等因素对粗产品酸度和外观质量的影响。 Di (2-ethylhexyl) phthalate (DOP) was prepared from phthalic anhydride and 2-ethylhexanol using solid acid niobium pentoxide as esterification catalyst. The reaction is to rapidly generate the intermediate mono-2-ethylhexyl phthalate, which is then esterified to form the diester DOP. The reaction from monoester to diester is a typical second-order reaction, and the rate constant and activation energy of the second-order reaction are determined. The recycling of the catalyst was studied. The effects of reaction time, reaction temperature and the amount of catalyst on the acidity and appearance quality of the crude product were discussed.