  In this article, we investigate the representation ring (or Green ring) of
the Drinfeld double $D(H_n(q))$ of the Taft algebra $H_n(q)$, where $n$ is an
integer with $n>2$ and $q$ is a root of unity of order $n$. It is shown that
the Green ring $r(D(H_n(q)))$ is a commutative ring generated by infinitely
many elements subject to certain relations.
