In this paper, we obtain global O(1/ √ k) pointwise and O(1/k) ergodic convergence rates for a variable metric proximal alternating direction method of multipliers (VM-PADMM) for solving linearly constrained convex optimization problems. The VM-PADMM can be seen as a class of ADMM variants, allowing the use of degenerate metrics (defined by noninvertible linear operators). We first propose and study nonasymptotic convergence rates of a variable metric hybrid proximal extragradient (VM-HPE) framework for solving monotone inclusions. Then, the abovementioned convergence rates for the VM-PADMM are obtained essentially by showing that it falls within the latter framework. To the best of our knowledge, this is the first time that global pointwise (resp. pointwise and ergodic) convergence rates are obtained for the VM-PADMM (resp. VM-HPE framework).2000 Mathematics Subject Classification: 90C25, 90C60, 49M27, 47H05, 47J22, 65K10.Key words: alternating direction method of multipliers, variable metric, pointwise and ergodic convergence rates, hybrid proximal extragradient method, convex program.• by letting H k = βI, β > 0, and θ = 1, the resulting method becomes similar to Algorithm 7 in [2], where a composite structure of f is considered and ergodic convergence rates were obtained under the additional conditions that B = I in (1) and the dual solution set of (1) be bounded.Contributions of the paper. We obtain an O(1/k) global convergence rate for an ergodic sequence associated to the VM-PADMM (2)-(4) with θ ∈ (0, ( √ 5 + 1)/2), which provides, for given tolerances ρ, ε > 0, triples (x, y,γ), (r x , r y , r γ ) and scalars ε x , ε y ≥ 0 such that r x ∈ ∂ εx f (x) − A * γ , r y ∈ ∂ εy g(y) − B * γ , r γ = Ax + By − b, max r x * x , r y * y , r γ * γ ≤ ρ, ε x +ε y ≤ ε,