Title: A New Phase of Tau-Charm Physics -- BESIII and its Preliminary Results


The BESIII experiment running at the Beijing electron-positron collider(BEPCII) at the tau-charm energy region is operational since 2008. A total of 200 million J/psi events and 100 million psi' events have collected. The performance of the BESIII detector will be described and preliminary results will be reported.