Rate parameters and gradient correlations for nucleic acids are very important to engineering investigations of the separation of DNA products by gradient elution chromatography. Before carrying out computer simulations for gradient process, these rate parameters and gradient correlation must be determined from the experimental data. In this work, moment method was used to calculate the equilibrium adsorption constants (Ki) as a function of the ionic strength (I) of the mobile phase for different sizes of oligonucleotides from the isocratic elution data and later, these coefficient values were used in the computer simulation to predict the elution behavior. This analysis can eliminate extensive experimental trial and error and hence suitable for separation of oligonucleotides and DNA in a more effective manner.