  A connected graph is called a bi-block graph if each of its blocks is a
complete bipartite graph. Let $\mathcal{B}(\mathbf{k}, \alpha)$ be the class of
bi-block graph on $\mathbf{k}$ vertices with given independence number
$\alpha$. It is easy to see that every bi-block graph is a bipartite graph. For
a bipartite graph $G$ on $\mathbf{k}$ vertices, the independence number
$\alpha(G)$ satisfies $\ceil*{\frac{\mathbf{k}}{2}} \leq \alpha(G) \leq
\mathbf{k}-1$. In this article, we prove that the maximum spectral radius
$\rho(G)$ among all graphs $G$ in $\mathcal{B}(\mathbf{k}, \alpha)$, is
uniquely attained for the complete bipartite graph $K_{\alpha,
\mathbf{k}-\alpha}$.
