Using variational analysis, we study the linear regularity for a collection of finitely many closed sets. In particular, we extend duality characterizations of the linear regularity for a collection of finitely many closed convex sets to the possibly nonconvex setting. Moreover the sharpest linear regularity constant can also be dually represented under the subsmoothness assumption. Key words. approximate projection theorem, linear regularity, normal cone, subsmoothness AMS subject classifications. 90C31, 90C25, 49J52, 46B20