根据分子结构的特点和分子性能的结构基础，探讨了烷基萘的密度与折光指数之间的定量关系，发现烷基 萘的密度与折光指数的对数之间存在着良好的线性关系，据此发展了一种密度和折光指数的相互预测方法（用折 光指数预测密度或根据密度预测折光指数）。对４３种烷基萘的计算结果表明，折光指数预测结果的平均误差为０．２０％，密度预测结果的平均误差为 ０．４５％。 According to the molecular structure and the structural basis of the molecular properties, the quantitative relationship between the density of alkylnaphthalene and the refractive index was explored. It was found that there was a good linear relationship between the density and the logarithm of the refractive index. This developed a mutual prediction of density and refractive index (using refractive index to predict density or predict refractive index from density). The calculation of 43 alkyl naphthalene shows that the average error of the refractive index prediction is 0.20% and the average error of the density prediction is 0.45%.