Objective To investigate the influence of Zafirlukast on the inflammatory factors and immune function of patients with seasonal allergic asthma.Methods 182 patients with seasonal allergic asthma from the department of respiratory in our hospital were selected and divided into two groups, 91 cases in each group.The control group treated with budesonide and formoterol fumarate powder for inhalation, the experiment group received Zafirlukast on the basis of the control group,serum levels of inflammatory cytokines,peripheral blood T lymphocyte subsets,serum immunoglobulin levels, lung function,and the clinical effect were compared after the treatment.Results Compared with the control group, serum levels of TNF-,IL-4,IL-6 were lower, level of IL-10 was higher in the experiment group after treatment, CD8 +T lymphocyte levels was lower, CD3 +, CD4 +T lymphocyte and CD4 +/CD8 +ratio levels were higher after treatment, serum levels of IgE, IgG, IgA were lower after treatment, levels of PEF,FEV1 ,FEV1/FVC were higher after treatment, the difference was statistically significant (P<0.05).The effective rate in the experiment group 94.51% was higher than the control group 81.32% (P<0.05).Conclusion Zafirlukast can significantly reduce the levels of serum inflammatory factors in patients with seasonal allergic asthma, improve the cellular immune function, reduce the level of immunoglobulin, effectively improve lung function, shorten the length of hospital stay, has better clinical curative effect.