Objective To compare the effects of moxilfoxacin and levolfoxacin on community acquired pneumonia (CAP) in the elderly .Through analyzing the related failed factors of the treatment by moxilfoxacinto improving the quality of clinical treatment and reducing the costs. Method 65 cases were treated with moxilfoxacin and 60 cases were given levolfoxacin. The clinical and bacterial efifcacy were evaluated, and the related risk factors was tested by Logistc regression analysis. Resluts The clinical efifcacy rate, mortality rate and bacterial efifcacy rate were 53.85%, 16.92%and 83.72%in moxilfoxacin group, which were all signiifcantly different from 36.67%, 23.33%and 70.73%in levolfoxacin group (P<0.05). The Logistc regression analysis showed that the age (OR=1.981, 95%CI 1.526-2.572), complications≥2 (OR=3.671, 95%CI 1.482-9.093), fluid and electrolyte imbalance (OR=2.384, 95%CI 1.620-3.508), renal insufifciency (OR=2.121, 95%CI 1.362-3.303) and leafy pneumonia (OR=4.338, 95%CI 1.468-12.819) were independent risk factors for treatment failure. Conlusion The clinical curative effect in elderly patients with severe CAP treated by moxilfoxacin is signiifcantly higher than levolfoxacin. But treatment failure rate is also higher. The result relates to a variety of factors. We should cope with CAP by a comprehensive evaluation to screen high-risk patients, in order to make an effective treatment strategy and improve the prognosis.