  In this paper, we study the following biharmonic Choquard type equation
\begin{align*}
  \begin{split}
  \left\{
  \begin{array}{ll}
  \gamma\Delta^2u-\beta\Delta u=\lambda u+(I_\mu*F(u))f(u),
  \quad\mbox{in}\ \ \mathbb{R}^4,
  \displaystyle\int_{\mathbb{R}^4}|u|^2dx=c^2>0,\quad u\in H^2(\mathbb{R}^4),
  \end{array}
  \right.
  \end{split}
  \end{align*} where $\gamma>0$, $\beta\geq0$, $\lambda\in \mathbb{R}$,
$I_\mu=\frac{1}{|x|^\mu}$ with $\mu\in (0,4)$, $F(u)$ is the primitive function
of $f(u)$, and $f$ is a continuous function with exponential critical growth.
We can prove the existence of ground state normalized solutions for the above
problem when the nonlinearity $f$ satisfies some conditions.
