We have studied dilepton production during the chemical equilibration of baryon_rich quark_gloun matter, and found that due to the slowing down of the cooling rate and the high initial temperature of the quark_gloun matter(QGM) produced at RHIC energies, the quark phase contribution to dileptons with intermediate mass es is significantly heightened, thus, the enhancement of dileptons with intermed iatc masses should be an signal for the QGM formation. Since this enhancement ca n compensate the dilepton suppression caused by increasing the initial chemical potential, therefore, the dilopton suppression may not be a signal for the quar k_gloun matter formation.