Answer
$-2xyz$
Work Step by Step
div $\textbf{F}=\nabla \cdot \textbf{F}=\nabla\cdot\langle x^{2}yz,-xy^{2}z,-xyz^{2}\rangle$
$=\frac{\partial}{\partial x}(x^{2}yz)+\frac{\partial}{\partial y}(-xy^{2}z)+\frac{\partial}{\partial z}(-xyz^{2})$
$=2xyz+-2xyz+-2xyz=-2xyz$