Definition: The patient has a history of sexual contact and clinical symptoms, but no gonococcus gonorrhoeae can be found in the secretions. Etiology: mostly caused by Chlamydia trachomatis and by a small percentage of ureaplasma mycoplasma two microorganisms, followed by Trichomonas vaginalis, herpes virus can also be the pathogen, and the disease is now widely circulating. Symptoms: incubation period of 1-4 weeks, male patients show painful urination, difficulty in urination, a small amount of thin white mucus flowing from the urethra in the morning, squeezing the urethra by hand to overflow. Female patients mostly have no obvious conscious symptoms, but have leucorrhea. Complications: often due to repeated infection or untimely treatment, improper treatment, easy to combine acute epididymitis, urethritis, Reiter syndrome, and even cardiovascular neurological lesions, women with complications of urethritis, cervicitis, infertility, newborns through the birth canal infection caused ophthalmia, pneumonia. Diagnosis: History of sexual contact, discharge in the urethra, difficulty in urination but negative gonorrhea test can be diagnosed, if there is no obvious discharge, urine can be taken for sediment microscopy, under high magnification microscope, 10-15 multinucleated leukocytes per field of view can also help to diagnose. If available, urethral secretions can be taken for pathogenic bacteria examination.