A molecular figure about chain-alkane is regarded as a multi- dimension system in mechanic vibration. A atom, or a group in molecule was treated as the dispersion mass-points in it, and the chemical bond in molecule as the spring linking the dispersion mass-points. The mass of the mass-point is showed by its atom mass, and the rigidity of the spring by the bond energy. The intrinsic vibration frequencies (ω_i) was calculated by the method of mechanical vibration theory. The basic frequency (ω_o) and sum-frequency (Σ_(ω_i)) in the molecule were taken as structural information index and the quantitative structure-property relationship ( QSPR) model was established: P_i = αω_0 + bΣ_(ω_i) + c . It was used as multivariate regression analysis for 15 kinds of physical properties about chain-alkane, and the results demonstrated that there were good correlations between the frequency and the properties with coefficient r = 0.9190～1.0000.

Key words: ALKANE, TORSIONAL VIBRATION, TOPOLOGY