Let (E,F, µ) be a probability space and (E,D(E)) a conservative Dirichlet form on L2(µ).

Corresponding to known results on Orlicz-Sobolev inequalities which are stronger than the Poincare ́ inequality, this paper studies the weaker Orlicz-Poincare ́ inequality. More precisely, for any Young function Φ whose growth is slower than quadric, the Orlicz-Poincare ́ inequality ‖f‖2Φ ≤ CE (f, f), µ(f) = 0 is studied by using the well-developed weak Poincare ́ inequalities, where E is a conser-vative Dirichlet form on L2(µ) for some probability measure µ. In particular, criteria and concrete sharp examples on this inequality are presented for Φ(r) = rp(p ∈ [1, 2)) and Φ(r) = r2 log−δ(e + r2)(δ> 0). Concentration of measures as well as analogous results for non-conservative Dirichlet forms are also obtained. As an application, con-vergence rate of porous media equations is described. AMS subject Classification: 60H10, 47D0