Objective To evaluate the sonographic characteristics of peripheral focal inflammation of lung, and to improve the diagnosis and differential diagnosis potency of sonography for pulmonary peripheral lesions. Methods The sonogram of 44 patients with peripheral focal inflammation of lung were retrospectively analyzed and compared with the sonogram of other lesions. Independent variables included lesion’s margin, echotype, the secondary change of visceral pleura, the angulation of lesion’s inner surface and air bronchogram. Lesion’s nature was as dependent variable. The data was analyzed by Logistic regression analysis. Pathological results were confirmed by biopsy. Results The angulation of lesion’s inner surface and air bronchogramwere significant factors affecting the diagnosis of peripheral focal inflammation of lung( P lt;0. 01) . Compared to the pathological yield by biopsy, angulation of lesion’s inner surface being acute angle for diagnosis of peripheral focal inflammation of lung had an accuracy rate of 82. 6% , a sensitivity of 72. 7% , a specificity of 84. 7% , a positive predictive value of 51. 0% , and a negative predictive value of 93. 4%. Conclusions The acute angle of lesion’s inner surface and air bronchogram are sonographic characteristics of peripheral focal inflammation of lung. Bedside lung ultrasound is useful to the diagnosis of peripheral focal inflammation of lung.