Abstract. In a series of works [18,21,19,20,23,22], Geiß-Leclerc-Schröer defined the cluster algebra structure on the coordinate ring C[N (w)] of the unipotent subgroup, associated with a Weyl group element w. And they proved cluster monomials are contained in Lusztig's dual semicanonical basis S * . We give a set up for the quantization of their results and propose a conjecture which relates the quantum cluster algebras in [4] to the dual canonical basis B up . In particular, we prove that the quantum analogue Oq[N (w)] of C[N (w)] has the induced basis from B up , which contains quantum flag minors and satisfies a factorization property with respect to the 'q-center' of Oq[N (w)]. This generalizes Caldero's results [7,8,9] from ADE cases to an arbitary symmetrizable Kac-Moody Lie algebra.