Abstract: Objective In order to evaluate the therapeutic effect,to screen effective drugs for AIDS,and to find out the changes of patient's condition,it is necessary to develop an objective method to quantitate the levels of viral load of the patients before and after treatment.Method Differential PCR(D-PCR) was used to co-amplify the target HIV-1 gag gene and reference template β-globin gene,so as to determine the level of HIV replication quantitatively.The levels of HIV DNA in the peripheral blood mononuclear cells of 8 patients with AIDS were determined quantitatively.Results The levels of the provirus of the 8 patients ranged from 0.508-2.210 copies/μg DNA,there were differences in the levels of replication and integration.Conclusion It is the authors' opinion that this method is easy to control with an advantage of reliability,quickness and reproducibility,It is suitable to measure clinical specimens,and provides an objective evidence for the evaluation of responses to therapeutic intervention.

Key words: PCR, differential, AIDS, Provirus