  Using (447.9 $\pm$ 2.3) million $\psi$(3686) events collected with the BESIII
detector, the decays of $\chi_{cJ} \rightarrow \phi\phi$ ($J$=0, 1, 2) have
been studied via the decay $\psi(3686)\rightarrow\gamma\chi_{cJ}$. The
branching fractions of the decays $\chi_{cJ} \rightarrow \phi\phi$ ($J$=0, 1,
2) are determined to be $(8.48\pm0.26\pm0.27)\times10^{-4}$,
$(4.36\pm0.13\pm0.18)\times10^{-4}$, and $(13.36\pm0.29\pm0.49)\times10^{-4}$,
respectively, which are the most precise measurements to date. From a helicity
amplitude analysis of the process $\psi(3686) \rightarrow \gamma \chi_{cJ},
\chi_{cJ}\rightarrow \phi\phi, \phi\rightarrow K^{+}K^{-}$, the polarization
parameters of the $\chi_{cJ} \rightarrow \phi\phi$ decays are determined for
the first time.
