In this talk we present our work on equivariant K-theory of spherical varieties. After explaining our general result, a description of the equivariant K-rings for smooth complete spherical varieties, we present its applications to the wonderful compactifications of minimal rank symmetric varieties. In particular, we will work out our theorem in the case of complete collineations. This is joint work with Soumya Banerjee (Ben Gurion Univ.).