Abstract: The molecular connectivity index (Xi), electrotopological state index (En) and molecular electrongativity distance vector (Mk) of 42 volatile compounds in nutmeg essential oil were calculated. A quantitative structure-retention relationship (QSRR) model for retention index (RI) of volatile compounds in nutmeg essential oil was deduced by leaps and bounds regression with the correlation coefficient of 0.980. The calculated values were in good agreement with experimental data with an average error of 2.71%. This model exhibited excellent stability and predictability through the evaluation by Jackknife method and LOO cross-validation procedure. The regression results showed that the Xi，En and Mk could characterize molecular structure and explain the nature of chromatographic retention index.

Key words: nutmeg essential oil, volatile components, chromatographic retention index, topological index, quantitative structure-retention relationship (QSRR)