Abstract: ［Abstract］Objective　To investigate the incidence ， gender， season and age distribution of Mycoplasma pneumoniae（MP）infection in children in Kunming. Methods　From January 2009 to December 2013，11，473 cases of respiratory infections with suspected Mycoplasma pneumoniae infection in our hospital were given serum test of the antibody of Mycoplasma pneumoniae．Results　In recent five years， a total of 11，473 cases of respiratory tract infections in children in our hospital received MP antibody detection，the positive case was 2952 cases，the positive rate was 25.73%. The positive rate in male children and female children was 21.89% and 30.87%， respectively， the difference was statistically significant（ χ2＝118.294，P＜0.001）. The highest antibody positive rate（28.41%）was found in the winter season，followed by in spring（28.24%） and autumn（23.07%）. The lowest positive rate（9.86%）was in 0-1year group，followed by 1-3 years group and 4-6 years group， the highest positive rate（30.43%）was in > 6 years group， the trend chi-square test χ2＝178.208，P＜0.001， showing that the positive rate was growing with the age. The highest positive rate（33.75%）was found in 2011， compare with other years， the differences were statistically significant. Conclusion　There was MP infection prevalence in Kunming in 2011. The positive rate in children is growing with the age，the peak of infection is in spring and winter， so the detection and prevention of mycoplasma pneumonia should be strengthened.