Objective To investigate the clinical effect of Spleen Aminopeptide Oral Solution (SAOS) in the prophylactic treatment of seasonal allergic rhinitis (AR) and its effect on immune function. Methods A total of 52 patients with seasonal AR who were treated in the Affiliated Hospital of Inner Mongolia Medical University from May 2015 to May 2019 were selected as the research objects, and they were divided into group A (n=20), group B (n=20) and group C(n=12) according to the random number table method. Patients in group A received SAOS alone, group B received both SAOS and Loratadine, group C received Loratadine alone. The three groups were given different preventive intervention before the onset of AR. The influence of different drugs on the symptoms, quality of life, combined medication and T helper lymphocyte (Th) subsets (Th1/Th2) cytokines of patients with seasonal AR were compared among the three groups. Results At 2 weeks of treatment, the total score and sub item score of rhino-conjunctivitis quality of life questionnaire (RQLQ) in group B were lower than those in group C, the differences were statistically significant (P＜0.05). At 4 weeks of treatment, the total symptom score of group B was lower than that of group C, the difference was statistically significant (P＜0.05). The total score and sub item score of RQLQ in group B were lower than those of group C, the differences were statistically significant (P＜0.05). At 12 weeks of treatment, the scores of nasal symptoms and emotional reactions of group B were lower than those of group C, and the nasal symptoms score of group A was lower than those of group C, the differences were statistically significant (P＜0.05). In the pollen peak period (4 and 8 weeks of medication), the score of combined medication of group B was lower than that of group A and group C, the differences were statistically significant (P＜0.05). Cytokine detection of Th1/Th2 showed that the levels of interleukin (IL)-2, interferon-γ (IFN-γ), IL-4, IL-10 in group A after treatment were higher than those before treatment, and the differences were statistically significant (P＜0.05). The levels of IL-2, IFN-γ, tumor necrosis factor-α(TNF-α), IL-4, IL-6, IL-10 in group B after treatment were higher than those before treatment, the differences were statistically significant (P＜0.05). The levels of IL-2, IFN-γ, IL-4, IL-10 in group C after treatment were higher than those before treatment, the differences were statistically significant (P＜0.05). There were no significant differences in the levels of cytokines among the three groups after treatment (P＞0.05). Conclusion The combination of SAOS and Loratadine in the prophylactic treatment of seasonal AR can effectively relieve the symptoms, improve the quality of life,and affect the expression of Th1/Th2 cytokine levels, the curative effect is remarkable.