Abstract： Objective To investigate the clinical efficacy of botulinum toxin A(BTX-A)on autumn pollen-induced SAR and compare the difference of different doses of BTX-A.Methods This study was a randomized,double-blind exploratory clinical trial.The included patients were divided into a high-dose BTX-A group(25 U/side),a low-dose BTX-A group(12.5 U/side)and a saline control group(0.9％normal saline).The total nasal symptom score(TNSS),total ocular symptom score(TOSS),visual analogue scale(VAS)and rhinoconjunctivitis quality of life questionnaire(RQLQ)were used to evaluate the nasal and ocular symptoms and quality of life of the patients at week 2,4 and 8.Results Totally,29 patients were finally included in this study.The TNSS of the high-dose BTX-A group at week 4 and 8 after treatment,and the TOSS of the high-dose BTX-A group at week 2,4,8 after treatment were significantly lower than those before treatment and the control group.The RQLQ also showed a downward trend.The TNSS of the high-dose BTX-A group at week 4 after treatment was significantly lower than that of the low-dose group,and the TOSS of the high-dose BTX-A group at week 4 after treatment was significantly lower than that of the low-dose group,indicating that high-dose BTX-A had a more obvious improvement on the nasal and eye symptoms of SAR.BTX-A can significantly reduce the VAS of nasal congestion,runny nose and nasal itching in SAR patients at week 4 after treatment,and can last until the week 8.At the same time,BTX-A can significantly reduce the VAS of eye itching,eye swelling,tearing and eye pain in SAR patients at week 2 after treatment,and can last until the week 8.Conclusion BTX-A can effectively relieve the clinical symptoms of SAR,with high safety and few side effects,and is worthy of clinical promotion.