With the beam test facility at IHEP, measurements on the BESIII performance have been successfully finished. The whole test operation, which included measurements on the time resolution of TOF, the energy and spatial resolution of EMC, the performance of a full length MDC prototype and the efficiency of Muon detector, has lasted for two years. The measurement results agreed with the design specifications of BESIII, providing real and reliable data for comparison between the electronics calibration and the edition performance, and early instructions for the data analysis and the simulation approach of the spectrometer.

　　The BEPC beam test facility, constructed in Mar.2003, is the first mid-high energy test beamline in our country based on high energy accelerator, which provides an experimental platform for the studies and performance measurements on the spectrometer. The facility, in virtue of the performance improvement and high efficiency of the BEPCII Linac, has made great improvement in its own performance during the two years following its construction. At present, the counting rate for a single particle reaches 2 HZ at maximum, while for multiple particles ( operation momentum at 800MEV, consisting of electron, π meson and proton) the counting rate reaches 8-9 HZ at maximum. After BEPCII starts running, its linac would be able to furnish electron beams at 50HZ, 100 bunches per second. The beam test facility would add the counting rate for the secondary single particles and improve operational efficiency. By that time, the scope of application of the facility will be further enlarged.