  Using about $226\times 10^6$ $\jpsi$ events and $106\times 10^6$
$\psi^{\prime}$ events collected with the BESIII detector at the BEPCII
$e^+e^-$ collider, the Dalitz plot of $\etap \to \eta \pi^+ \pi^-$ decay is
studied, the direct measurement of $a^{0}_{0}(980)-f_{0}(980)$ mixing is
performed, $X(2120)$ and $X(2370)$ are observed in the $\pi^+\pi^-\eta^\prime$
invariant mass spectrum, $\psi^{\prime}\to\gamma\pi^0$ and
$\psi^{\prime}\to\gamma\eta$ are observed for the first time, and the decays
$\chi_{cJ}\to\gamma V$ ($V=\phi$, $\rho^0$, $\omega$) are studied.
