Abstract. Let φ : X → Y be a map of Q-factorial Mori dream spaces. We prove that there is a unique Cox lift Φ : X → Y of Mori dream stacks coming from a homogeneous homomorphism R(Y ) = R(Y) → R(X ), where Y is a canonical stack of Y and X is obtained from X by root constructions, and φ is induced from Φ by passing to coarse moduli spaces. We also apply this techniques to show that a Mori dream quotient stack is obtained by roots from its canonical stack.