To address the relationship between female infertility and genital inflammation of chlamydia trachomatis (CT), we took samples from the cervix and fallopian tube of 147 cases of female infertility and investigated the rate of CT infection by using polymerase chain reaction (PCR) assay. 60 cases of normal pregnant women were chosen as controls. The results showed that in the infertile group the CT positive rates for fallopian tubes and cervices were 15.66% and 22.45% respectively, whereas in the control group the tubal positive rate was 3.33%. There was significant difference between the two groups in tubal positive rate (P < 0.05). Youngsters and workers were the high risk population of genital infection of CT. These results indicate that genital infection of CT is an important factor causing infertility; in that disease, the tubal infection of CT is even more important. Besides the damage to tubal mucosa and smooth muscle, CT infection causes tubal adhesion and obstruction. As a result it impairs the function of the fimbriae and leads to infertility.