To evaluate the auxiliary diagnostic value of Japanese respiratory society (JRS) scoring system for the rapid diagnosis of Mycoplasma pneumoniae pneumonia (MP) in inpatients with community acquired pneumonia (CAP). The clinical data of inpatients with CAP between January 2013 and Novermber 2013 were retrospectively analyzed. The gold standard for identification of MP infection was determined by both positive culture and real time polymerase chain reaction (PCR) methods. Blood and sputum culture were used to detect other bacteria and fungi, and real time PCR to detect Chlamydia and Legionella pneumonia and the common respiratory viruses. Diagnostic test results consistency inspection was performed by Kappa test and continuous variable analysis was performed using t test. Data from 139 CAP inpatients were analyzed. An aetiological diagnosis was made for 61 patients (43.9%). Thirty-five cases (25.2%) were diagnosed as MP infection by the gold standard, while 72 cases (52.0%) by the JRS scoring system. The sensit