  In this paper, we investigate the Green ring $r(H_{n,d})$ of the generalized
Taft algebra $H_{n,d}$, extending the results of Chen, Van Oystaeyen and Zhang
in \cite{Coz}. We shall determine all nilpotent elements of the Green ring
$r(H_{n,d})$. It turns out that each nilpotent element in $r(H_{n,d})$ can be
written as a sum of indecomposable projective representations. The Jacobson
radical $J(r(H_{n,d}))$ of $r(H_{n,d})$ is generated by one element, and its
rank is $n-n/d$. Moreover, we will present all the finite dimensional
indecomposable representations over the complexified Green ring $R(H_{n,d})$ of
$H_{n,d}.$ Our analysis is based on the decomposition of the tensor product of
indecomposable representations and the observation of the solutions for the
system of equations associated to the generating relations of the Green ring
$r(H_{n,d})$.
