The theory of vague set is a new theory in the field of fuzzy information processing. In this paper, we make an attempt to extend the approaches of computing attributes reductions in the literature. We first review the basic notion termed vague rough set by combing rough set theory and vague set theory. Then, by using the vague rough lower approximation distribution in the vague decision information systems, the new concept of the discernibility matrix is proposed. Finally, an approach for extracting decision rules from the vague decision information systems is proposed. These studies provided a new avenue to uncertain fuzzy knowledge acquisition.