ObjectiveTo evaluate the significance of change in T help cell 17(Th17) and regulatory T cell （Treg） in HIVinfected patients. Methods106 HIVinfected patients and 30 healthy volunteers were selected. Flow cytometry was used to detect the CD4+ T ,Th17 and Treg cells in peripheral blood. HIV RNA levels in serum were tested by RTPCR.ResultsCD4+ T cells were 13-702/uL, 19 patients were ≤200/uL (group A), 32 were 201-350/uL（ group B）, 26 were 351-500/uL（group C）, 29 were >500/uL（group D）; All were significantly lower than （798-1 130/uL） in healthy control group（P<0.05）. The percentage of Th17 cells in CD4+ T cells were (0.73±0.21)%,(1.52±0.33)%, (2.92±0.46)% , and (3.74±0.58）% in group A, B ,C and D, respectively, which were all lower than (4.90±1.43)％ of control group（P<0.05）; The percentage of Treg cells in CD4+ T cells were (9.78±2.15)%, (7.23±1.72)%, (5.69±1.67)% , and (4.62±0.97)% in group A, B,C and D,respectively, group A, B and C were higher than (4.43±0.97)％ of control group（P<0.05）, but group D had no significant difference compared with control group（P>0.05）. HIV RNA levels were (0-5.36)×107copies/mL in HIVinfected patients, the average levels of HIV RNA were (5.36±1.21)×106copies/mL ; HIV RNA levels in group A,B,C and D were（6.24±1.36）×107copies/mL，（4.36±1.02) ×106 copies/mL，（5.78±1.67）×104copies/mL，and （3.54±1.25) ×103copies/mL ,respectively，there was significant difference between each group(P<0.05), HIV RNA levels were negatively correlated with CD4 +T cells count. ConclusionHIV infection can result in the decrease of Th17 and CD4+T cells， imbalance of Th17/Treg cells， and negative correlation with HIV RNA levels.