This paper presents preparation with modeling and theoretical predictions of mechanical pro- perties of compatibilized functionally graded and uniform distribution polyethylene/modified montmorillonite nanocomposites manufactured by solution and melt mixing techniques. The morphology is studied by Scanning Electron Microscopy (SEM) and comparisons are made between two techniques. Young’s modulus of nanocomposites for functionally graded and uniform distributions is calculated using a genetic algorithm and is then compared with the results of other theoretical prediction models mentioned in the literature as well as experimental results. It is found that the melt mixing technique is the preferred prepara- tion method, and the results obtained from the theoretical predictions of genetic algorithm procedure are in good agreement with the experimental ones.