采用ＣＮＤＯ／Ｓ—ＣＩ方法结合引入外场的微扰理论．计算了一系列内桂醛衍生物的分子二阶极化率，并且从微观上探讨了该类化合物取代基的电子性质、取代基位置及其取代数目对分子二阶非线性光学系数的影响。结果表明，该类化合物有较高的分子二阶极化率；取代基的电子性质和取代方式对其有明显的影响。 The CNDO / S-CI method combined with the perturbation theory introduced into the field. The second order polarizabilities of a series of cinnamic aldehyde derivatives have been calculated and their effects on the second order nonlinear optical constants have also been investigated microscopically on the electronic properties, substituent positions and number of substitutions. The results show that these compounds have higher second order polarizability; the electronic properties of substituents and substitution patterns have a significant impact.