Objective：To investigate the first chest high resolution CT（HRCT）imaging manifestations of corona virus disease 2019（COVID-19）and its pathological basis. Methods：A retrospective analysis of the first chest HRCT images of 61 patients with COVID-19 clinically diagnosed in Nanjing from January 25 to February 18，2020. Lesion distribution，number，location and morphology were analyzed. Results：Lesions were found in the first HRCT of 61 patients，with bilateral lung distribution in 55 cases（90.1%），unilateral lung distribution in 6 cases（9.9%），left lung distribution 2 cases（3.3%）and right lung distribution 4 cases（6.6%）；subpleural distribution of lung in 36 cases（59.0%），25 cases（41.0%）were found subpleural and central distribution at the same time；4 cases（6.6%）got one lesion，57 cases（93.4%）got two and more lesions；ground-glass lesions appeared in 56 cases（91.8%），solid lesions in 5 cases（8.2%），cord-like lesions in 3 cases（4.9%），coexisting lesions of two or more forms in 9 cases（14.8%）；air bronchogram in 35 cases（57.4%），refined net sign in 38 cases（62.3%），paving stone sign in 32 cases（52.5%），halo sign in 6 cases（9.8%）；thickening of blood vessels in 32 cases（52.4%）；5 cases（8.2%）with pleural effusion，3 cases（4.9%）with pericardial effusion，3 cases（4.9%）with enlarged mediastinal lymph nodes；and 7 cases（11.5%）had pleural thickening. Conclusion：HRCT is preferred imaging method of COVID-19. The first chest HRCT manifestations have certain characteristics. Therefore，it could help the early diagnosis of COVID-19 based on epidemiology，clinical manifestations，and nucleic acid testing.