了解咳嗽患儿肺炎支原体（ＭＰ）的感染情况。方法对经青霉素或头孢唑啉钠治疗３ｄ以上无效的咳嗽患儿１８７例进行ＰＣＲＭＰ－ＤＮＡ检查。结果阳性率２９．９％，５岁以下阳性率为３２．７％，５岁以上阳性率为２５．３％，二者无显著性差异（Ｐ＞０．０５），喘息性疾患阳性率显著高于普通支气管炎及肺炎，咳嗽时间越长阳性率越高。结论ＭＰ感染在５岁以下小儿并不少，它与喘息性疾患密切相关，故对长期咳嗽小儿应重视ＭＰ－ＤＮＡ检查。 Understand the infection of Mycoplasma pneumoniae (MP) in children with cough. Methods A total of 187 children with cough treated by penicillin or cefazolin sodium for more than 3 days were tested for PCR-DNA. Results The positive rate was 29.9%, the positive rate was 32.7% under 5 years old, and the positive rate was 25.3% over 5 years old, with no significant difference (P> 0.05). The positive rate of asthmatic disease was significant Higher than ordinary bronchitis and pneumonia, the longer the cough, the higher the positive rate. Conclusion MP infection in children under 5 years of age is not less, it is closely related with wheezing, so long-term cough children should pay attention to MP-DNA examination.