Abstract: OBJECTIVE To explore the pathogenic effect of exogenous pathogens on pelvic abscess so as to provide guidance for clinical treatment of pelvic abscess.METHODS Totally 105 patients with pelvic abscess who were hospitalized from Jan 2014 to Jun 2016 were chosen as the study group, and 107 patients with non-infectious benign adnexa mass who were hospitalized during the same period were set as the control group.The medical records of the two groups of patients were retrospectively analyzed, the cervical secretions were collected from the two groups of patients so as to detect Chlamydia trachomatis, Mycoplasma hominis, and Ureaplasma urealyticum; the culture of Neisseria gonorrhoeae was carried out, and the diameters of pelvic masses of the two groups of patients were recorded according to the result of B ultrasound.RESULTS There was significant difference in the use of condom between the study group and the control group (14.29% vs 41.12%,P＜0.01); there was significant difference in the placement of intrauterine device (37.14% vs 9.35%,P＜0.01).The positive rate of C.trachomatis of the study group was 22.34%, higher than 5.61% of the control group; the positive rate of M.hominis of the study group was 31.52%, higher than 9.80% of the control group, and there was significant difference between the two groups (P＜0.01).The incidence rate of U.urealyticum infection was 54.35% in the study group, 55.88% in the control group, and there was no significant difference between the two groups.The incidence rate of N.gonorrhoeae infection was 2.56% in the study group, 0.00% in the control group, and there was no significant difference between the two groups.CONCLUSIONThe use of condom may reduce the prevalence rate of pelvic inflammatory diseases, however, the women who use the intrauterine device are more likely to have the pelvic inflammatory diseases. C.trachomatis is the major species of pathogen causing the pelvic abscess.The positive rate of M.hominis of the study group is higher than that of the control group, which indicates that the M.hominis may also be one of the species of pathogens causing the pelvic inflammatory diseases.The positive rate of U.urealyticum is high in both groups; since the U.urealyticum is both pathogenic bacteria and symbiotic bacteria, it does not show such significant clinical significance that the U.urealyticum is simply detected positive.