Using QSRR modelling, an E index was designed based on the H. P. Schultz MTI index. The E index is a molecular descriptor consisting of a vector and adjacent and distant matrices. Linear regressions were obtained by means of a QSRR - GLC study of a set of 11 cis and 11 trans alquenes characterized by the Ecis, Etrans indices. The correlation indices (r) were 0.97495 and 0.95767 respectively. It was demonstrated that in the linear regressions above, a smaller r was obtained, when the E index was replaced by the refractive molar index taken as reference (IRM). The discrimination E values for cis and trans alquenes were obtained by multiplying by (-1) the distance matrix diagonal elements, corresponding to the carbon atoms that support the π bonds in cis alquenes