According the terminology of Bethesda 2001, the unsatisfactory cervical cytology can be categorized into specimen rejected, or specimen processed and examined, but unsatisfactory for evaluation of epithelial abnormality. Most of the unsatisfactory cervical cytology was due to scanty epithelial cells, which was defined by less than an estimated 8,000 to 12,000 well-visualized squamous cells for conventional smears. Follow-up of unsatisfactory smear found an increased rate of cervical preinvasive and invasive lesions. Thus, an unsatisfactory smear deserves careful follow-up and studies. Although the Bethesda system allows criteria modification in cases of hysterectomy, pelvic irradiation therapy, or chemotherapy, no studies investigated the clinical factors related to the incidence of unsatisfactory smear. Thus, the investigators designed this trial to study the clinical factors relating to unsatisfactory cervicovaginal smear.The list of patients who received Papanicolaou smear between March 2006 and August 2006 in our hospital will be obtained from the Pathological Department first. Then the investigators will review the medical records from HIS system and pathologic files of these patients. On estimation, 7,437 cases will be enrolled for analysis. Clinical parameters for analysis include: age, gravidity, parity, abortion, menopause, location of Pap smear, history of pelvic malignancy, pelvic irradiation, cervical conization, hysterectomy; at pregnancy; three months postpartum; vaginal bleeding, vaginal abnormal discharge, intrauterine device, and cervical polyp found during pelvic examinations. Patients who missed any of above data will be excluded for analysis. The investigators will use univariate and multivariate analysis for data processing and statistic analysis to find out the relationship between clinical parameters and unsatisfactory cervicovaginal Pap smears.