  We use experimental data on $e^{+}e^{-} \rightarrow \eta\pi^{+}\pi^{-}$ and
$\tau^{-} \to \eta\pi^{-}\pi^{0}\nu_{\tau}$ to test conservation of vector
current (CVC) by comparing the predicted hadronic spectrum and branching
fraction with the $\tau$ decay data. Based on the corresponding $e^+e^-$ data
and CVC, we also calculate the branching fraction of $\tau^{-} \to
\eta^\prime\pi^{-}\pi^{0}\nu_{\tau}$ decay.
