Objective:To investigate the efficacy of Mirabegron plus microecologics for the treatment of overactive bladder(OAB)in elderly women.Methods:In this prospective study, 104 patients diagnosed with OAB in the urology department of our hospital between February 2020 and December 2021 were recruited.The participants were randomly divided into two groups, with 52 in each.Group I was treated with Mirabegron alone(50 mg, qd)and Group Ⅱ was treated with Mirabegron(50 mg, qd)plus probiotics(3.5 g, bid)for 12 weeks.The efficacy was evaluated based on results before and after treatment, using measurements including the daily frequencies of urinary urgency, nocturia, daytime urination, urge incontinence and bladder capacity.The overactive bladder symptom score(OABSS), the quality-of-life score, and the number of lower urinary tract infections during treatment were also collected.Results at different treatment stages(week 4 and week 12)were compared within each group and between the two groups by Dunnett's test.Results:The symptoms of OAB in both groups were significantly improved after 12 weeks' treatment.In the group(Group Ⅱ)receiving the combination of two drugs, results from four measurements, the frequency of 24-hour urination(6.6 ± 0.7 vs.7.1 ± 1.2), the frequency of 24-hour urinary urgency(0.6 ± 0.6 vs.1.1 ± 0.7), the frequency of daily nocturia(0.8 ± 0.7 vs.1.3 ± 0.6)and the quality-of-life score(1.2 ± 0.7 vs.2.3 ± 0.8), were all significantly more favorable than in the group(Group I)treated with Mirabegron( P<0.05).The incidence of lower urinary tract infections and constipation was significantly reduced in the group with drug combination treatment. Conclusions:The efficacy of Mirabegron combined with microecologics for the treatment of OAB is better than that of Mirabegron alone, and the incidence of adverse events such as infections and constipation is also lower.