Objective:To analyze the dynamic changes of total HIV-1 DNA in peripheral blood mononuclear cells (PBMC) following highly active antiretroviral therapy (HAART) in HIV-1/HCV co-infected patients.Methods:Thirty patients with HIV-1/HCV co-infection without anti-HCV treatment (co-infected group) and 42 HIV-1 infected patients with initial treatment (mono-infected group) admitted to Guangzhou Eighth People’s Hospital from May 2015 to December 2017 were retrospectively analyzed. The virological and immunological responses of the two groups at 12, 24, 48, 72 and 96 weeks after HAART, the changes of total HIV-1 DNA in PBMC and its relationship with peripheral blood HIV-1 RNA and T lymphocyte subsets were observed. SPSS 22.0 statistical software was used to analyze the data.Results:The plasma HIV-1 virus inhibition rate, CD4 + T cells and CD4 + /CD8 + ratio increased and the total HIV-1 DNA in PBMC decreased in both groups after HAART. The inhibition rate of HIV RNA at week 72 in co-infected group was significantly lower than that in the mono-infected group ( χ2=7.93, P<0.01). Compared with the mono-infected group, the CD4 + T cells at week 12, 24, 72 and 96 after HAART were lower in the co-infected group ( U=313.50, 329.00, 286.00 and 204.50, P<0.05 or <0.01). The CD4 + /CD8 + ratio at week 48 in the co-infected group was lower than that in the mono-infected group ( U=294.50, P<0.05). The total HIV-1 DNA of the co-infected group at baseline and week 12 was lower than that of the mono-infected group ( U=362.00 and 359.00, P<0.01 or <0.05). There was no significant correlation between total HIV-1 DNA in PBMC and HIV-1 RNA or CD4 + /CD8 + ratio in both groups ( P>0.05). There was no correlation between total HIV-1 DNA and CD4 + T cells in HIV-1/HCV co-infected group ( b=-0.001, P>0.05), but it had negative correlation in the mono-infected group ( b=-0.001, P<0.05). Conclusion:Total HIV-1 DNA in PBMC was significantly decreased after HAART in HIV-1/HCV co-infected patients. Co-infected with HCV may delay the decrease of total HIV-1 DNA after HAART in patients with HIV-1 infection.