Mycoplasma pneumoniae, an important pathogen of community acquired pneumonia,are becoming more and more resistant to macrolide. The study aim is to optimize anti-infection therapy.

Mycoplasma pneumoniae was one of important atypical pathogens of community acquired pneumonia. As lack of cell wall, β-lactam medicines were invalid, however, macrolides, tetracyclines and quinolones were effective. But from 2001, many countries reported macrolide- resistant Mycoplasma pneumoniae. Typically, erythromycin was first-line antibiotic medicine. With the resistance increasing, Mycoplasm pneumonia treatment will become more and more difficult. Thus, optimization of Mycoplasm pneumonia antibiotic therapy is very important.

Inclusion Criteria:

1. Confirmed community acquired pneumonia
2. 60ys≥age≥18 ys
3. Respiratory symptom (cough accompanied by little or no sputum)
4. New infiltration showed by chest radiology(x-ray or CT)
5. Lung signs was not obvious
6. White blood cell<10,000/mm3
7. Without underlying diseases or mild

Exclusion Criteria:

1. Age<18ys or >60ys
2. Pregnancy or breast-feeding
3. Over one week after the onset of symptoms
4. HIV infection
5. Recent 90-day hospitalized history(length of stay greater than 2 days)
6. Live in nursing homes or rehabilitation hospitals
7. Taken macrolides or quinolones medicines before enrollment