Objective:To evaluate the effect and safety of Kangfuyan Capsules(抗妇炎胶囊) for treating pelvic inflammatory disease (PID) in patients with chronic pelvic pain (CPP) in a multicenter,randomized,controlled,double-blind,parallel-group clinical trial.Methods:Totally,240 PID patients with CPP were randomized into 2 groups using a computer generated random number at a 1∶1 ratio from 10 hospitals in China between September 2014 and November 2015.Patients received either oral Kangfuyan Capsules or Gongyanping Capsules(宫炎平胶囊,control);the regimen for both groups comprised 4 capsules (3 times daily)for 12 weeks,with follow-up visit 4 weeks after treatment.The visual analogue scale (VAS) scores,clinical responses,remarkable cure rates for each symptom,and quality of life scores were assessed at baseline,and after 1,2,and 3 months.Adverse events were also recorded.Results:The VAS scores were significantly lower(P＜0.05),whereas the clinical responses,remarkable cure rates for lower abdominal pain,uterine tenderness,adnexal mass,and adnexal tenderness,and health-related quality of life (EQ-5D) scores were higher in the Kangfuyan group than in the control group at 3 months (P＜0.05).Common treatment-related adverse events included high hepatic enzyme levels,reduced hemoglobin levels,and elevated platelet counts,although all the adverse events were either mild or moderate in severity.Conclusion:Compared with Gongyanping therapy,Kangfuyan therapy yielded markedly better analgesia effects for CPP caused by PID,with obvious long-term efficacy and good safety.(Registration No.ChiCTR190022732)