OBJECTIVE To detect the incidence of chlamydial infection in female genital tract and it's relationship with tubal infertility. METHODS Fourty-eight infertile women underwent laparoscopies were divided into study group (n = 32) and control group (n = 16). Samples were taken from the upper genital tract (including endometrium, tubal fimbriae, peritoneal fluid and pelvic adhesion) and lower genital tract (cervix). The monoclonal direct immunofluorescent method was used to assay chlamydia trachomatis the results of these two groups were compared. RESULTS The positive percentage of cervical clamydial infections between the two groups were not significant lydifferent (P > 0.05). But there showed a significant difference between the two groups if compared by the incidence of the whole genital tract 32.5% and 10.2% (P < 0.01). The tubal positive percentage is 66.7% in the study group. Which is the highest among other locations such as cervix, endometrium, etc (P < 0.05). CONCLUSIONS This study indicates that fallopian tube is a high prevalent site of chlamydial infection, and chlamydial infection in female genital tract is a principal pathogenic factor of tubal infertility. Early laparoscopy for tubal infertility and chlamydia trachomatis sampling is the key method for early diagnosis and treatment of chlamydia trachomatis.