Reiter's Syndrome is a special clinical type of reactive arthritis with the triad of arthritis, urethritis and conjunctivitis as clinical features. It often presents as sudden acute arthritis accompanied by unique extra-articular skin and mucosal symptoms. It is currently believed that there are two forms of this disease: sexually transmitted and dysenteric. The former is mainly seen in young men aged 20 to 40, and in most cases the genitals are infected with Chlamydia trachomatis. Reiter's syndrome is rare in women, children and the elderly. They usually acquire the dysenteric type after intestinal bacterial infection, mainly Shigella, Salmonella, Yersinia and Campylobacter. The onset of Reiter's syndrome is related to infection, genetic markers (HLA-B27) and immune disorders. The pathological changes of the synovium are non-specific inflammation. This disease is more common in young men. The incidence rate abroad ranges from 0.06% to 1%. There are no statistical data reports in this regard in China. </p