Abstract： Objective To analyze the influence of Bw4 motif carried by HLA-A, B loci on CD4 T cell count and viral load of primary HIV infectors. Methods The technique of SSP-PCR was employed to detect the HLA-A, B allele typing in 95 HIV infectors. And the roles of Bw4 motif carried by HLA-A, B loci on CD4 T cell count and viral load were analyzed. Results ( 1 ) The population frequency of HLA-A, B loci carrying Bw4 motif was respectively 32. 6% (31/95) and 60. 0% (57/95). The population frequency of Bw4/4, Bw4/6, Bw6/6 located on HLA-B was 21.1% (20/95), 38.9% (37/95) and 40.0%(38/95) respectively. (2)Compared with those with CD4 T cell count less than 500/μl, more Bw4 motifs were expressed on HLA-A, B loci of patients with CD4 cell count more than 500/μl (mean rank,56. 7 vs 41.6,U=749. 5, P＜0. 01 ). Moreover, the fewest infectors were those with HLA-A, B carrying 3 Bw4 motifs and CD4 T cell count fewer than 500/μl( 1 case). And secondly were those with HLA-A, B carrying 0 or 3 Bw4 motif and CD4 cell count more than 500/μl (7 cases,x2 = 12. 6, P ＜0. 01 ). (3)The infectors with HLA-A, B loci carrying 3 Bw4 motifs had more CD4 T cell count( median: 65 1/μl)and less viral load (lg median: 3.43 ) than those with HLA-A, B carrying 0 or 1 Bw4 motif(430 and 425/μl,4. 48 and 4. 40).And the difference was significant (all P ＜0. 05 ). However, the CD4 cell count and viral load between the patients with HLA-A, B carrying 2 Bw4 motifs and 3 Bw4 motifs were insignificantly different (P ＞0. 05).(4) Irrespective of Bw4 motif on HLA-A locus, the infectors HLA-B carrying Bw4/4 homozygote had more CD4 cell count (median: 538/μl) and less viral load (lg median: 3.53) than those carrying Bw4/6 heterozygote or Bw6/6 homozygote ( 433/μl and 427 /μl,4. 29 and 4. 48, all P ＜ 0. 05 ) . However,irrespective of Bw4 motif on HLA-B, the CD4 cell count and viral load were insignificantly different between the infectors HLA-A carrying Bw4 motif and non-Bw4 motif. Conclusion Bw4 motifs can increase the CD4 cell count and decrease the viral load of patients with primary HIV infection. Maybe Bw4/4 homozygote on HLA-B plays a role of delaying the disease progression.