Objective: To compare the features of chest CT findings between coronavirus disease 2019（COVID-19） and bacterial pneumonia

and to improve the ability to differentiate between the two diseases in clinical practice.Methods: We retrospectively analyzed the CT data of 40 cases of COVID-19

and compared them with the CT findings of 40 patients with bacterial pneumonia who attended our hospital from January 1

2017 to March 1

2020. Results: COVID-19 showed significantly more frequent intralobular septal thickening（82.5% vs 10%

P < 0.001） and significantly less frequent centrilobular nodules（5% vs 20%

P < 0.05） and tree-in-bud sign（7.5% vs 25%

P <0.05） compared with bacterial pneumonia. The proportions of lung segment involvement were 8.2 ± 2.7 and 4.7 ± 1.8 for COVID-19 and bacterial pneumonia

respectively. The involvement area score was 6.2 ± 1.3 for COVID-19 and7.6 ± 2.4 for bacterial pneumonia

and there was a predominance in the inferior lobes. The subpleural area was involved in 65% and 20% of patients with COVID-19 and bacterial pneumonia

respectively. Compared with bacterial pneumonia

COVID-19 had significantly higher percentages of single ground glass opacity（GGO）（32.5% vs 12.5%

P < 0.05） and multiple GGOs（37.5% vs 15%

P < 0.05）. Conclusion: COVID-19 mainly involves the subpleural area

and frequently affects the lung segments. It shows more frequent intralobular septal thickening and GGO but less frequent centrilobular nodules and tree-in-bud sign than bacterial pneumonia.