CAS, Inst High Energy Phys, Beijing 100039, Peoples R China
It is of great interest to build a high luminosity accelerator in tau-charm energy region. The physics interest in this energy region is briefly reviewed. Events rate and events number at different energy in one year's data taking are estimated under typical luminosity of 10(33) cm(-2)s(-1). It is pointed out that the luminosity of a newly designed accelerator should be optimized between psi" and psi(4160), the peak luminosity should be determined by the events rate which the trigger system, detector electronics and data acquisition system could handle.