In this study, we determined the physical parameters of W UMa type contact binaries and their stability of mass transfer with different stellar mass ranges over a broad space by applying the basic dynamical evolution equations of the W UMa type contact binaries using accretor and donor masses between 0.079 and 2.79 M⊙. In these systems, we have studied the three subclasses of W UMa systems of A-, B- and W-type contact binaries using the initial and final mass ranges and we investigated different stellar and orbital parameters for the subclasses of W UMa systems. We examined the stability of the W UMa type contact binaries using the orbital parameters such as critical mass ratio, Roche lobe radius of the donor star and mass ratio of these systems. Thus, we computed the observed and calculated physical parameters of A-, B- and W-type W UMa systems. Moreover, we determined the combined and color temperatures to classify the three subclasses of the systems. Also, we presented the result of the internal stellar structure and evolution of W UMa type contact binaries by using the polytropic model.