A comparison between deuteron and alpha particle, has been done from many aspects. Different comparative methods have been used to study alpha and deuteron properties. Diffraction model has been applied to deuteron and alpha particles. The radial region of sensitivity has been tested using the distance of the closest approach where Notch test was applied to study the sensitivity of the optical model parameters. The reaction cross section and reflexion coefficients ηL of the deuteron and alpha elastically scattered by light nuclei (6,7Li, 9Be and 11B) have been used for the comparison between the two projectiles under consideration. The imaginary potentials for deuteron and alpha elastically scattered by 7Li has been used also, to study the difference between alpha and the deuteron. It was observed that deuteron has a signature of halo properties. Agreement between theoretical analysis and experimental data has been obtained for deuteron and alpha elastically scattered by light nuclei (6,7Li, 9Be and 11B).