Objective To investigate the high risk factors of chlamydia (CT) infection in female.Methods Enzyme linked immunosorbent assay was used to detect 120 cases of gynecological clinic,including 60 cases asymptomatic patients before abortion and 60 cases patients with symptoms of mild genital itching,vaginal secretions slight increased.CT antigen in uterine cervix were detected,and the relationship between its symptoms,age,birth time,contraception,cervical condition,the number of sexual partners,mycoplasma and CT infection were analyzed.Results Among 120 cases,there were 28 cases of CT positive,positive rate was 23.3％ (28/120).CT infection rate of symptomatic and asymptomatic patients was 16.7％,30.0％ respectively,the difference was not significant(P＞0.05).The CT infection rate of patients' age younger than 30 years was 27.8％,higher than older than 30 years (10.0％),the difference was significant(x2=3.975,P＞0.05).The CT infection rate of patients had multiple sexual partners in nearly lyear was 62.5％,higher than that had one sexual partner(9.0％),the difference was significant(x2=37.42,P＞0.05).The CT infection rate of patients didn't use contraceptive tools was 29.1％,higher than that used contraceptive tools(12.2％),the difference was significant(x2=4.319,P＜0.05).Conclusion The symptoms of CT infection are no specificity,should be targeted at screening for patients have high-risk factors,such as age less than 30 years old,have multiple sexual partners nearly 1 year and don' t use contraceptive tools.