  With the ability to run above 4~GeV, the BESIII experiment located in the
Beijing Electron Positron Collider (BEPCII), has becoming a pioneer in
searching and studying charmoniumlike states ($XYZ$ particles). In 2013, BESIII
Collaboration discovered a charged charmoniumlike state $Z_c(3900)$, which is
confirmed immediately experimentally, and provides the best candidate for a
four quark state by now. Continuous studies by BESIII Collaboration show new
decay behavior of $Z_c(3900)$, and there are possible partner particle
$Z_c(4020)/Z_c(4025)$ existing. By scanning above 4~GeV, BESIII also reveals
the potential connection between $Y(4260)$ and $X(3872)$ for the first time,
which may help us understand $XYZ$ particles in a new sight.
