Abstract: Objective To investigate relationship between human immunodeficiency virus type I(HIV-1)B'specific cytotoxic T lymphocytes(CTL)and disease progression in Chinese HIV-1 infected individuals.Methods We stimulated HIV-1B'Gag specific CTL isolated from 58 HIV-1 infected individuals,with 54 overlapping peptides which were spanning the entire Gag protein of HIV-1 clade B',then determined function of CTL using an Enzyme-Linked Immunospot (ELISPO T)assay.Results There were varieties of epitopes that were recognized by specific CTL in Chinese HIV-1 infected individuals.The breadth and magnitude of CTL response were reversly correlated with the HIV-1 viral load significantly(r=-0.374,P=0.004;r=-0.285,P=0.030),the breadth of CTL response was correlated with the true counts of CD₄⁺ T lymphocytes significantly(r=0.425,P=0.001).The breadth of CTL response of long term non progressors was significantly superior to that of asymptomatic HIV infected and acquired immunodeficiency syndrome(A IDS)patients(P= 0.001;P=0.005).Conclusion There are specific CTL that response against different HIV-1B'Gag peptides in Chinese HIV-1 infected individuals and the function of CTL are correlated with disease progression.