Objective: To explore the expression of IL-27, Th17 cells and CD4+CD25+ regulatory T cells (Treg) as well as its associated cytokines in peripheral blood of patients with allergic rhinitis (AR). Method: From March 2012 to May, the peripheral blood of 24 cases of AR patients (AR group) and 16 cases of healthy volunteers (control group) was collected, and the percentage of Th17 cells and Treg cells in the peripheral blood was detected by flow cytometry (FCM); the levels of IL-27, IL-17 and IL-10 in serum was detected by ELISA. Result: The percentage of Th17 cells in AR group and the control group was 1.76% ± 0.60% and 0.59% ± 0.17%, respectively. It was higher in AR group than in control group, and the difference between two groups was statistically significant (P < 0.01); Treg cell percentage in AR group and control group was 1.65% ± 0.79% and 5.03% ± 1.92%, respectively. AR group was significantly lower than the control group, and the difference between two groups was statistically significant (P < 0.01). Serum IL-17 expression level (668.68 ± 62.59) pg/ml in AR group was higher than that of the control group (587.30 ± 28.00) pg/ml, and the difference was statistically significant (P < 0.01); the levels of IL-27 in AR group and the control group were (23.15 ± 10.12) pg/ml and (52.97 ± 10.08) pg/ml, and the difference was statistically significant (P < 0.01); IL-10 expression level (14.29 ± 6.16) pg/ml in AR group serum was lower than that in the control group (31.32 ± 21.20) pg/ml, and the difference between two groups was statistically significant (P < 0.01). In the peripheral blood of AR patients, there was a negative correlation between Th17 cell percentage and Treg cell percentage, IL-10 (r = -0.794, -0.483, P < 0.01), and a negative correlation between IL-27 and Th17 cell percentage, IL-17 (r was -0.758 and -0.519 respectively, P < 0.01). IL-27 was positively correlated with Treg cell percentage and IL-10 (r = 0.722, 0.646, P < 0.01), and percentage of Treg cells and IL-10 was positively correlated (r = 0.622, P < 0.01). There was no correlation between IL-17 and Th17 cell percentage, Treg cell percentage, IL-10 (r = 0.225, -0.183, -0.176, P > 0.05). Conclusion: In the peripheral blood of AR patients there was a reduction of IL-27 level and imbalance of Th17/Treg cell function. IL-27 on Th17/Treg cells adjustment may play an important role on the pathogenesis of the AR.