OBJECTIVE To investigate the diagnoses and treatment of interstitial cystitis (IC). METHODS The clinical data of 16 IC patients were analyzed respectively. The patients with urinary frequency, urgency, suprapubic pain and chronic pelvic pain. They were misdiagnosed as chronic cystitis, pelvic inflammation, endometriosis, cystophthisis and urethral syndrome, and were diagnosed finally by the means of pathology or cystoscopy. Among the 16 patients, 4 cases had the operation of ileal reservoir, Two cases had sigmoid-cysto-plasty, and 10 cases had drug treatment. The methods of IC diagnosis and treatment were discussed with the review of literature. RESULTS The pelvic ache disappeared completely in 4 cases after the operation of ileal reservoir; Two cases after cystoplasty felt lightly discomfortable in perineum occasionally, and their bladder capacity was above 350 ml, no recurrence after operation having been found after follow-up for 24 months and 33 months; Ten cases treated with non-operative treatment improved obviously, with the O'Leary-Sant IC symptom index and IC problem index decreased from 15.4 +/- 4.1, 9.4 +/- 2.7 to 4.1 +/- 2.1 and 5.1 +/- 3.9, respectively. CONCLUSIONS Sufficient attention should be paid to the diagnosis and differential diagnosis of IC; Early diagnosis and therapeutic alliance with manifold measures can relieve the patients' symptom and improve the quality of life.