Natl Lab Heavy Ion Accelerator, Ctr Theoret Nucl Phys, Lanzhou 730000, Peoples R China
; Chinese Acad Sci, Inst Nucl Res, Shanghai 201800, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
From thermodynamic relations, the initial values of the quark-gloun plasma from relativistic nucleus-nucleus collisions are obtained. From these initial values we have studied the dilepton production on the basis of the (3 + 1) dimensional relativistic hydrodynamic model established by the present authors, and found that with increasing incident energy a characteristic plateau indicating the formation of quark-gluon plasma appears in the total yield, which may be tested in future experiments in CERN and Brookhaven.