This paper presents the application of Analysis of Variance (ANOVA) approach to study effects of different aggregate properties on the resilient modulus behavior of unbound aggregates. In a recent research project at the University of Illinois, stress-dependent resilient modulus characterization models, in the form proposed for use by the Mechanistic Empirical Pavement Design Guide (MEPDG), were established for three different aggregate types (dolomite, limestone, and uncrushed gravel) using a statistically well-formulated laboratory test matrix. Such a consistent database enabled the evaluation of the model parameter dependence on different aggregate properties, such as particle shape, type and amount of fines, and moisture condition, using the Analysis of Variance (ANOVA) approach. From the statistical analyses, aggregate particle type or angularity was found to have a significant effect on the resilient moduli. At low fines content, the type of fines and moisture state in relation to optimum moisture condition were found to be somewhat insignificant as far as the regression parameter values are concerned. The effect of amount of fines became quite significant especially when the amount of fines was increased.