Abstract: OBJECTIVE To analyze the levels of serum autoantibodies and cervical mucus inflammatory factors in infertile women with Ureaplasma urealyticum (UU) infection. METHODS Totally 80 infertile patients with combined UU infection treated in the Reproductive Medicine Center of Haikou Maternal and Child Health Hospital from Oct.2019 to Oct.2021 were selected as the study group, and 100 infertile patients without combined UU infection during the same period were selected as the control group.The basic data and the expressions of serum anti human chorionic gonadotropin antibody (HCG-Ab) and antisperm antibody(AS-Ab), antiovarian antibody (AO-Ab), antiendometrial antibody (AEM-Ab), anticardiolipin antibody (AC-Ab) as well as the tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin(IL)-6, IL-8 in cervical mucus during ovulation of patients in the two groups were compared. RESULTS The percentage of the patients with spontaneous abortion in the study group was 23.75% (19/80), which was higher than that in the control group (P＜0.05).The positive rates of serum AS-Ab, AO-Ab and AEM-Ab of the patients in the study group were 61.25% (49/80), 22.50% (18/80) and 48.75% (39/80), respectively, all higher than those in the control group (P＜0.05).The levels of TNF-α, IFN-γ, IL-6 and IL-8 in cervical mucus were (175.68±36.12) ng/ml, (79.61±8.26) ng/ml, (0.35±0.23) pg/ml and (0.93±0.37) pg/ml, respectively, all higher than those in the control group (P＜0.05). CONCLUSION Infertile women with co-infected UU had higher rates of positive serum autoantibodies and higher levels of inflammatory factors in cervical mucus.UU might be involved in the pathological process of infertility by inducing the expression of autoantibodies and inflammatory damage of cervical tissue.