By adopting the coupling by reflection and choosing an auxiliary function which is convex near infinity, we establish the exponential convergence of diffusion semigroups (Pt)t≥0 with respect to the standard Lp‐Wasserstein distance for all p∈[1,∞). In particular, we show that for the Itô stochastic differential equation
dXt=dBt+b(Xt)dt,if the drift term b is such that for any x,y∈double-struckRd,
⟨b(x)−b(y),x−y⟩≤rightK1|x−y|2,right|x−y|≤L;right−K2|x−y|2,right|x−y|>Lholds with some positive constants K1, K2 and L>0, then there is a constant λ:=λ(K1,K2,L)>0 such that for all p∈[1,∞), t>0 and x,y∈double-struckRd,
Wp(δxPt,δyPt)≤Ce−λt/pright|x−y|1/p,rightif4.pt0.28em|x−y|≤1;right|x−y|,rightif4.pt0.28em|x−y|>1where C:=C(K1,K2,L,p) is a positive constant. This improves the main result in where the exponential convergence is only proved for the L1‐Wasserstein distance.