  The K-rings of non-singular complex pro jective varieties as well as quasi-
toric manifolds were described in terms of generators and relations in an
earlier work of the author with V. Uma. In this paper we obtain a similar
description for complete non-singular toric varieties. Indeed, our approach
enables us to obtain such a description for the more general class of torus
manifolds with locally standard torus action and orbit space a homology
polytope.
