Objective: To investigate the factors associated with CD4⁺ /CD8⁺ T lymphocyte ratio normalization in acquired immunodeficiency syndrome (AIDS) patients after antiretroviral therapy (ART). Methods: The data of 1 188 human immunodeficiency virus (HIV)/AIDS patients from the national ART reporting system in Yuxi City, Yunnan Province between January 1, 2006 and December 31, 2016 were retrospectively collected and analyzed. The rate of CD4⁺ /CD8⁺ T lymphocyte ratio normalization after ART was calculated by lifetable. Cox proportional hazard models were used to analyze the factors associated with CD4⁺ /CD8⁺ T lymphocyte normalization in AIDS patients after ART. The Wilcoxon rank sum test was used for comparison between groups. Results: The follow-up time was 3.8 (1.0-10.8) years. CD4⁺ /CD8⁺ T lymphocyte ratio normalization was documented in 95 patients with the rate of 1.89 per 100 person-years (95% confidence interval(CI) 1.52-2.27) after ART. The average time from ART to CD4⁺ /CD8⁺ T lymphocyte ratio normalized was 9.4 years. The cumulative normalization rate was 0.02 for the first year, 0.06 for the third year, 0.11 for the fifth year, 0.19 for the seventh year and 0.37 for the ninth year. By Cox proportional hazard models, the probability of CD4⁺ /CD8⁺ T lymphocyte ratio normalization in patients infected HIV by heterosexual contacts was 3.709 (95%CI 1.781-7.726) times higher than those by intravenous injection. The probability of CD4⁺ /CD8⁺ T lymphocyte ratio normalization in patients with baseline CD4⁺ T lymphocytes of 350-499 and more than 500 cell/μL groups were 2.792 (95%CI 1.196-6.519) and 3.832 (95%CI 1.648-8.913) times higher than those with baseline CD4⁺ T lymphocytes less than 200 cell/μL, respectively. The probability of normalization after ART in patients with higher baseline CD4⁺ /CD8⁺ T lymphocyte ratio was higher than those with baseline CD4⁺ /CD8⁺ T lymphocyte ratio≤ 0.20 (hazard ratio>1, all P<0.01). Conclusion The CD4⁺ /CD8⁺ T lymphocyte ratio normalization in AIDS patients after ART is associated with baseline CD4⁺ T lymphocyte counts, baseline CD4⁺ /CD8⁺ T lymphocyte ratio and HIV transmission mode.