Objective To investigate the relationship between serum sPD-L1 expression and T lymphocyte subsets in allergic rhinitis (AR).Methods A total of 120 patients with AR admitted to our hospital from June 2018 to Feb 2020 were selected. In addition, 50 healthy physical examinees during the same period were included as the control group. ELISA method was used to determine the serum sPD-L1 levels and flow cytometry to check the CD3⁺, CD8⁺, CD4⁺ and CD4⁺/CD8⁺ levels in the both groups. Spearman was used to analyze the relationships between sPD-L1 and peripheral blood levels of CD3⁺, CD4⁺, CD8⁺ and CD4⁺/CD8⁺.Results The levels of sPD-L1 and CD4⁺/CD8⁺ in the AR group were significantly higher than those in the control group (all P<0.05). The levels of CD3⁺, CD4⁺, and CD8⁺ in the AR group were significantly lower than those in the control group (all P<0.05). Serum sPD-L1 level was negatively correlated with the levels of CD3⁺, CD4⁺, CD8⁺ (r₁=-0.754, r₂=-0.817, r₃=-0.691, P<0.05), and positively with CD4⁺/CD8⁺ (r=0.810, P<0.05).Conclusion The up-regulation of serum sPD-L1 expression in AR patients is closely related to the disorder of T lymphocyte subsets.