Abstract: Objective: To analyze the clinical features and treatment of Mycoplasma pneumoniae(MP) infection affecting the lung and other organs.Methods: Blood MP-IgM was tested with ELISA and cold agglutination.Eighty two cases diagnosed as MP infection were analyzed retrospectively.Results: Among all 84 cases,52.4% of the cases had respiratory symptoms;26.8% external visceral organs,especially.In the digestive system,nervous system and cardiovascular system.Following the macro macrocyclic lactone antibiotic treatment,80 patients were cured and 2 died.In the clinical laboratory test,72 cases had positive MP-IgM and 12.2% had positive MP-IgM with cold agglutination ≥ 1:32.Conclusions: The clinical features and X-ray photograms of MP infection lack specificity.For the digestive infection with unsatisfied treatment results and invaded multiple organs,the possibility of MP infection should be noted and relevant examination taken so as to make early diagnosis and apply proper treatment.