Trigger Efficiencies at BESIII

Trigger efficiencies at BESⅢ were determined for both the J/ψ and ψ data taking of 2009. Both dedicated runs and physics datasets are used; efficiencies are presented for Bhabha-scattering events, generic hadronic decay events involving charged tracks, dimuon events and ψ'→ π+π,J/ψ, J/ψ → l+l- events. The efficiencies are found to lie well above 99% for all relevant physics cases, thus fulfilling the BES design specifications.