Abstarct: In recent years, the so-called Isgur-Wise function (IWF) have been interested to study features of mesons in different models. To investigate IWF, we need wave function of mesons.Employing meson wave function we can study IWF for heavy-light mesons.IWF can well explain the meson transitions and their charge radii. In nonrelativistic frxamework we use Schrödinger equation and for relativistic and semirelativistic systems we use Salpeter, Klein- Gordon and DKP equations via different potentials. We have considered the attractive cases of D, B, Bs, Ds and mesons which have and structures. We have proceeded on the frxamework of nonrelativistic Schrödinger equation. We have studied IWF treatment for and mesons.In third chapter,we have shown IWF in semirelativistic structure and we have calculated parameters of IWF for some heavy-light and heavy mesons. In chapter four, we have investigated IWF for heavy-light mesons whithin relativistic frxamework. Also, we obtain IWF parameters for some spin one mesons such as J/ψ and Y mesons.Employing potential models, we have obtained masses of some heavy-lightand heavy mesons. We have compared our results with others which are in a good agreement with standard models.