Objective:To explore the CT findings of coronavirus disease 2019（COVID-19） in the early and advanced stages

and to improve the imaging diagnosis of the disease. Methods:The chest CT images of 24 patients diagnosed as COVID-19 were collected from January 2020 to February 2020 in the Southwest Medical University

including re-examination of CT images at admission and after admission

and analysis of all CT findings at early and advanced stages

and including the lesion distribution

morphology

density

internal features

peripheral and extrapulmonary manifestations. Result:All of the 24 COVID-19 patients

19（78.2%） had pulmonary manifestations. In the early stage

8 cases（33.3%） showed multi-leaf and multi-focus distribution

9 cases（37.5%） with single lamellar distribution

2 cases（8.3%） showed solitary round-like nodule with halo sign. The lesions are lobular

wedge-shaped or fan-shaped

and patchy or nodular

The density is mainly ground glass and consolidation

In this stage

only 1 case showed thickening of blood vessel and 1 case showed Bronchi sign; To the progression stage

In 9 cases

the distribution of single lobe was multilobe and multifocal in 4 cases

2 isolated round-like nodules were enlarged in the shape of a single leaf

In this stage

the lesions were increased and enlarged

and the multilobar and multifocal areas were partially fused with a large lamellar shape

The density mainly consists of ground glass shadow and ground glass mixed solid density shadow. In 19 cases

there were 9 cases（37.5%） with grid sign and Paving Stone Sign

8 cases（33.3%） with air bronchus sign

11 cases（45.8%） with vessel thickening sign

11 cases（45.8%） with the long axis parallel to the PLEURA

9 cases（37.5%） were distributed along the bronchovascular bundle. During the progressive stage

4 cases gradually spread to the whole lung and entered the critical stage. Conclusion: The Lung CT findings of COVID-19 are characteristic in the early and advanced stages. The diagnosis can be made by combining epidemiology and clinical symptoms

and the progression and prognosis can be evaluated.