Let Un be the unit polydisc of Cn and φ = (φ1, …, φn) a holomorphic self-map of Un. As the main result of the paper, it shows that the composition operator Cφ is compact on the Bloch space β(Un) if and only if for every ε > 0, there exists a δ > 0, such thatwhenever dist( φ( z), Un) < δ.……
