Abstract: Mycoplasma ovipneumoniae (Mo) is one of the main pathogens that causes mycoplasmal pneumonia in sheep and goats. The worldwide disease brings great economic loss to the industry. Currently, 3 detecting methods are commonly used for the disease. One applies the pathogen isolation and identification, but the isolation rates tend to be low. The second is the most popular molecular biology method. It employs PCR, LAMP, rapid touchdown PCR-lateral flow assay, or DNA probe technology for the diagnosis. The third one is the immunological detection by indirect hemagglutination, ELISA, immunohistochemistry or indirect immunofluorescence. The disease control largely relies on the vaccination and drug treatment. At present, inactivated vaccines are available, and various genetically engineered vaccines are being developed. The drug treatments of the infection include the uses of antibiotics, traditional Chinese medicine, and combination of traditional Chinese and western medicines. In recent years, the immune defense molecules were reported to show immunomodulatory and therapeutic effects on mycoplasmal pneumonia in sheep and goats. It is postulated to be a new approach for treating the disease. This article reviews the epidemiology, diagnosis, treatments, and research on vaccines of Mo infection.