Asymptotic behavior for nonlinear diffusion equations. We describe the long time asymptotics of nonlinear diffusion equations by two approaches: mass transportation techniques and entropy dissipation methods. They allow to prove exponential convergence of certain entropy functionals and the Wasserstein distance between probability measures. This class of equations contains as particular cases: heat equation, the porous medium-fast diffusion equation and nonlinear friction equations introduced in the study of granular media.