Abstract: Objective:To investigate novel coronavirus pneumonia(COVID-19) clinical manifestations, laboratory tests and chest CT features, and to deepen clinical understanding of the disease and to improve the awareness and prevention ability of public and hospital for public health emergencies. Methods:High resolution CT and three-dimensional reconstruction were performed in 12 patients with covid-19. The clinical manifestations, laboratory tests and chest CT features were analyzed and summarized. Results:The clinical manifestations of the confirmed cases were mainly fever and dry cough. The results of laboratory examination were mainly leucopenia, the decrease of lymphocyte count and percentage, the increase of serum C-reactive protein(CRP), the increase of muscle enzyme, liver enzyme and lactate dehydrogenase in varying degrees. The CT features of the chest were mainly distributed under the pleura of both lungs ground glass opacities(GGO) and lesions are mostly located under the pleura, in the field zone of the lung and the back of both lungs. Signs such as "paving stone sign", "bronchial inflation sign" and bronchial wall thickening can be seen locally. Pleural effusion and lymph node enlargement are relatively rare. Conclusions:The main clinical manifestations of patients with covid-19 are fever and/or cough. The CT findings of the chest show that there are obvious GGO in the peripheral and posterior lungs of both lungs, accompanied by normal or reduced leukocytes. Laboratory examination and CT findings of the chest are helpful for the early screening, diagnosis and treatment evaluation of patients with covid-19.