A clinical study was made on 71cases of Mycoplasma Pneumoniae Pneumonia from March, 86 to February, 89. The results were as follows; 1. Among the 315 cases of pneumonia, the incidence of mycoplasma infection was 22.5% 2. The peak incidence of age was between 5 to 9years of age (53.5%) 3. The sex ratio of male to female was 1.3:1 4. Monthly distribution showed relatively high frequency from October to January (59.2%) 5. Most common clinical symptoms were cough (98.6%) and then followed by fever (49.3%), coryza (19.7%). Rales were the most common finding (95.7%) and followed by pharyngeal injection (49.3%) and wheezing (18.3%) 6. The leukocyte counts in peripheral blood were most common in the range of 5000-10000/mm³ (47.9%) and the ESR was increased in 57.7%, and positive CRP cases were 87.3% 7. The most common radiologic finding of pulmonary infiltration was interstitial infiltration (45.1%) and then followed by disseminated lobular (39.4%) and lobar pneumonia (15.5%) 8. There are a few cases associated disease or complication: otitis media (5.6%), hepatitis (4.2%) acute glomerulonephritis, bronchial asthma and sinusitis (2.8%), thrombocytopenia (1.4%)