elastic scattering of α+ 40Ca are analyzed in the framework of optical model based on the α-cluster model of 40Ca. We adopted an independent α -cluster model to generate the α -cluster and matter densities of 40Ca. we pre -suggested the functional form of α -cluster density and fixed its parameters according to the available experimental data about the α -particle and 40Ca nuclei. The obtained α -cluster density of 40Ca is used to generate the real part of the optical potential. The single folding procedure is used to generate this real optical potential with two different effective α -α interactions. The real calculated potential supplied with an imaginary squared Woods Saxon potential are used to analyze 20 sets of experimental data on the energy range between 18 and 166 MeV. We found that our model is successful in reproducing the data for energies above 40 MeV and still doubtful for lower energies.